Silicate-based orange phosphors
View Patent ↗Novel orange phosphors are disclosed having the comprise silicate-based compounds having the formula (Sr,A 1 ) x ,(Si,A 2 )(O,A 3 ) 2+x :Eu 2+ , where A 1 is at least one divalent cation (a 2+ ion) including Mg, Ca, Ba, or Zn, or a combination of 1+ and 3+ cations; A 2 is a 3+, 4+, or 5+ cation, including at least one of B, Al, Ga, C, Ge, P; A 3 is a 1−, 2−, or 3− anion, including F, Cl, and Br; and x is any value between 2.5 and 3.5, inclusive. The formula is written to indicate that the A 1 cation replaces Sr; the A 2 cation replaces Si, and the A 3 anion replaces O. These orange phosphors are configured to emit visible light having a peak emission wavelength greater than about 565 nm. They have applications in white LED illumination systems, plasma display panels, and in orange and other colored LED systems.
1. A silicate-based orange phosphor having the formula (Sr 1−x M x ) y Eu z SiO 5 , wherein:
M is at least one of a divalent metal selected from the group consisting of Ba, Mg, Ca, and Zn;
0<x≦0.5;
2.6≦y≦3.3; and
0.001≦Z≦0.5;
wherein the phosphor is configured to emit visible light having a peak emission wavelength greater than about 565 nm;
subject to the proviso that y is not 3 when M is Ba.
2. The silicate-based orange phosphor of claim 1 , wherein the phosphor has the formula (Ba 0.05 Mg 0.05 Sr 0.9 ) 2.7 Eu z SiO 5 .
3. The silicate-based orange phosphor of claim 1 , wherein the phosphor has the formula (Ba 0.075 Mg 0.025 Sr 0.9 ) 3 Eu z SiO 5 .
4. The silicate-based orange phosphor of claim 1 , wherein the phosphor has the formula (Ba 0.05 Mg 0.05 Sr 0.9 ) 3 Eu z SiO 5 .
5. A silicate-based orange phosphor having the formula (Mg x Sr 1−x ) y Eu z SiO 5 , wherein:
0<x<1.0;
2.6≦y≦3.3; and
y+z is about equal to 3.
6. The silicate-based orange phosphor of claim 5 , wherein the phosphor has the formula (Mg x Sr 1−x ) 2.91 Eu 0.09 SiO 5 .
7. A silicate-based orange phosphor having the formula (Ca x Sr 1−x ) y Eu z SiO 5 , wherein:
0<x<1.0;
2.6≦y≦3.3; and
y+z is about equal to 3.
8. The silicate-based orange phosphor of claim 7 , wherein the phosphor has the formula (Ca x Sr 1−x ) 2.91 Eu 0.09 SiO 5 .
9. A silicate-based orange phosphor having the formula (Ba x Sr 1−x ) y Eu z SiO 5 , wherein:
0<x<1.0;
2.6≦y≦3.3; and
y+z is about equal to 3; and subject to the proviso that y is not 3.
10. The silicate-based orange phosphor of claim 9 , wherein the phosphor has the formula (Ba x Sr 1−x ) 2.91 Eu 0.09 SiO 5 .
11. A silicate-based orange phosphor having the formula (M 1−x Eu x ) y SiO 5 (F, Cl, Br), wherein:
M is at least one of a divalent metal selected from the group consisting of Sr, Ca, Ba, Zn, and Mg;
0.01≦x≦0.01; and
2.6≦y≦3.3.
12. The silicate-based phosphor of claim 11 , wherein M is Sr.
13. The silicate-based phosphor of claim 11 , wherein the halogen is F.
14. A silicate-based orange phosphor having the formula(M 1−x Eu x ) y SiO 5 (F,Cl,Br) 6z , wherein:
M is at least one of a divalent metal selected from the group consisting of Sr, Ca, Ba, Zn, and Mg;
0.01≦x≦0.1;
2.6≦y≦3.3; and
0<z≦0.1.
15. The silicate-based phosphor of claim 14 , wherein M is Sr.
16. The silicate-based phosphor of claim 14 , wherein the halogen is F.
17. A white LED comprising:
a radiation source configured to emit radiation having a wavelength ranging from about 280 to 560 nm; and
a silicate-based orange phosphor configured to absorb at least a portion of the radiation from the radiation source and emit light with a peak intensity in a wavelength greater than about 565 nm;
wherein the orange phosphor has the formula (Sr 1−x M x ) y Eu z SiO 5 ;
M is at least one of a divalent metal selected from the group consisting of Ba, Mg, Ca, and Zn;
0<x≦0.5;
2.6≦y≦3.3; and
0.001≦z≦0.5;
subject to the proviso that y is not 3 when M is Ba.
18. The white LED of claim 17 , further including a green phosphor configured to absorb at least a portion of the radiation from the radiation source and emit light with a peak intensity in a wavelength ranging from about 500 to 550 nm.
19. The white LED of claim 17 , further including a blue phosphor configured to absorb at least a portion of the radiation from the radiation source, and emit light with a peak intensity in a wavelength ranging from about 420 to 560 nm.
20. The white LED of claim 17 , further including a yellow phosphor configured to absorb at least a portion of the radiation from the radiation source, and emit light with a peak intensity in a wavelength ranging from about 530 to 590 nm.
21. An orange LED comprising:
a radiation source configured to emit radiation having a wavelength ranging from about 280 to 560 nm; and
a silicate-based orange phosphor configured to absorb at least a portion of the radiation from the radiation source and emit light with a peak intensity in a wavelength greater than about 565 nm;
wherein the orange phosphor has the formula (Sr 1−x M x ) y Eu z SiO 5 ;
M is at least one of a divalent metal selected from the group consisting of Ba, Mg, Ca, and Zn;
0<x≦0.5;
2.6≦y≦3.3; and
0.001≦z≦0.5;
subject to the proviso that y is not 3 when M is Ba.
22. An orange LED comprising:
a radiation source configured to emit radiation having a wavelength ranging from about 280 to 560 nm; and
a silicate-based orange phosphor having the formula (M 1−x Eu x ) y SiO 5 :F,Cl,Br, wherein:
M is at least one of a divalent metal selected from the group consisting of Sr, Ca, Ba, Zn, and Mg;
0.01≦x≦0.1; and
2.6≦y≦3.3.
23. A method of preparing a silicate-based orange phosphor having the formula (Sr 1−x M x ) y Eu z SiO 5 wherein:
M is at least one of a divalent metal selected from the group consisting of Ba, Mg, Ca, and Zn;
0<x≦0.5;
2.6≦y≦3.3; and
0.001≦z≦0.5;
the method selected from the group consisting of a sol-gel method, a solid reaction method, and a co-precipitation method;
subject to the proviso that y is not 3 when M is Ba, when the method is a solid reaction method.
24. The method of claim 23 , wherein the method is a co-precipitation method.
25. A method of preparing a silicate-based orange phosphor having the formula (M 1−x Eu x ) y SiO 5 (F,Cl,Br) H 6z , wherein:
M is at least one of a divalent metal selected from the group consisting of Sr, Ca, Ba, Zn and Mg;
0.01≦x≦0.1;
2.6≦y≦3.3; and
0<z≦0.1;
the method selected from the group consisting of a sol-gel method, a solid reaction method, and a co-precipitation method.
26. The method of claim 25 , wherein the method is a co-precipitation method.