Rare earth doped luminescent material
View Patent ↗A luminescent material includes an aluminate phosphor of formula I A 1+x Mg 1+y Al 10+z O 17+x+y+1.5z :Eu 2+ , R 3+ , where 0≦ x ≦0.4, 0≦ y ≦1 and 0≦ z ≦0.2. A is selected from Ca, Ba, and Sr and combinations thereof. The aluminate phosphor is doped with a rare earth ion (R 3+ ), which exists in stable multi-valence states in the luminescent material. R 3+ is selected from the group consisting of Sm 3+ , Yb 3+ , Tm 3+ , Ce 3+ , Tb 3+ , Pr 3+ and combinations thereof. Phosphors of formula I may be blended with other blue, yellow, orange, green, and red phosphors to yield white light phosphor blends. A lighting apparatus including such a luminescent material is also presented. The light apparatus includes a light source in addition to the luminescent material.
1. A luminescent material comprising an aluminate phosphor of formula I:
A 1+x Mg 1+y Al 10+z O 17+x+y+1.5z :Eu 2+ , R 3+ , wherein 0 ≦x≦ 0.4, 0 ≦y≦ 1 and 0 ≦z ≦0.2; and
wherein A is chosen to be Ba; and W is a trivalent rare earth ion selected from the group consisting of Sm3+, Pr3+ and/or combinations thereof.
2. The luminescent material of claim 1 , wherein mole fraction of europium ions (Eu 2+ ) ranges from about 0.05 to about 0.5.
3. The luminescent material of claim 1 , wherein the aluminate phosphor further comprises manganese ions (Mn 2+ ).
4. The luminescent material of claim 3 , wherein mole fraction of manganese ions (Mn 2+ ) is less than about 0.5.
5. The luminescent material of claim 1 , wherein the trivalent rare earth ions are present in an amount ranging from about 50 ppm to 10,000 ppm.
6. The luminescent material of claim 5 , wherein the trivalent rare earth ions are present in an amount ranging from about 2500 ppm to 7,000 ppm.
7. A luminescent material of claim 1 , further comprises LaMgAl 11 O 19 in an amount less than about 30 mole percent relative to the aluminate phosphor of formula I.
8. A luminescent material comprising an aluminate phosphor of formula II:
(LaMgAl 11 O 19 ) a (A 1+x Mg 1+y Al 10+z O 17+x+y+1.5z ) 1-a :Eu 2+ , R 3+
wherein 0≦a≦0.3;
0≦x≦0.4;
0≦y≦1;
0≦z≦0.2, and
wherein A is chosen to be Ba; and W is a trivalent rare earth ion selected from the group consisting of Sm3+, Pr3+ and/or combinations thereof.
9. The luminescent material of claim 8 , wherein mole fraction of europium ions (Eu 2+ ) ranges from about 0.05 to about 0.5.
10. The luminescent material of claim 8 , wherein the aluminate phosphor further comprises manganese ions (Mn 2+ ).
11. The luminescent material of claim 10 , wherein mole fraction of manganese ions (Mn 2+ ) is less than about 0.5.
12. The luminescent material of claim 8 , wherein the trivalent rare earth ions are present in an amount ranging from about 50 ppm to 10,000 ppm.
13. The luminescent material of claim 12 , wherein the trivalent rare earth ions are present in an amount ranging from about 2500 ppm to 7,000 ppm.
14. The luminescent material of claim 1 , further comprises an additional phosphor capable of emitting a lighting color selected from the group consisting of red, yellow, orange, blue and green emitting phosphors.
15. A lighting apparatus comprising:
a light source; and
a luminescent material radiationally coupled to the light source, and comprising an aluminate phosphor of formula A 1+x Mg 1+y Al 10+z O 17+x+y+1.5z :Eu 2+ , R 3+ ,
wherein A is chosen to be Ba; and W is a trivalent rare earth ion selected from the group consisting of Sm3+, Pr3+ and/or combinations thereof.
16. The luminescent material of claim 15 , wherein mole fraction of europium ions (Eu 2+ ) ranges from about 0.05 to about 0.5.
17. The luminescent material of claim 15 , wherein the aluminate phosphor further comprises manganese ions (Mn 2+ ).
18. The luminescent material of claim 17 , wherein mole fraction of manganese ions (Mn 2+ ) is less than about 0.5.
19. The luminescent material of claim 15 , wherein the trivalent rare earth ions are present in an amount ranging from about 50 ppm to 10,000 ppm.
20. The luminescent material of claim 19 , wherein the trivalent rare earth ions are present in an amount ranging from about 2500 ppm to 7,000 ppm.
21. The lighting apparatus of claim 15 , is a linear fluorescent lamp or a compact fluorescent lamp.
22. A lighting apparatus comprising:
a light source; and
a luminescent material radiationally coupled to the light source and comprising an aluminate phosphor of formula: BaMgAl 10 O 17 :Eu 2+ , Sm 3+ .
23. A lighting apparatus comprising:
a light source; and
a luminescent material radiationally coupled to the light source and comprising an aluminate phosphor of formula: BaMgAl 10 O 17 :Eu 2+ , Pr 3+ .
24. A lighting apparatus comprising:
a light source; and
a luminescent material radiationally coupled to the light source and comprising an aluminate phosphor of formula: BaMgAl 10 O 17 :Eu 2+ , Mn 2+ , Sm 3+ .
25. A lighting apparatus comprising:
a light source; and
a luminescent material radiationally coupled to the light source and comprising an aluminate phosphor of formula: BaMgAl 10 O 17 :Eu 2+ , Mn 2+ , Pr 3+ .