Phosphor for light sources and associated light source
View Patent ↗A phosphor for light sources, the emission from which lies in the short-wave optical spectral region, as a garnet structure A 3 B 5 O 12 . It is activated with Ce, the second component B representing at least one of the elements Al and Ga, and the first component A is terbium or terbium together with at least one of the elements Y, Gd, La and/or Lu. In a preferred embodiment, a phosphor having a garnet of structure (Tb 1-x-y RE x Ce y ) 3 (Al,Ga) 5 O 12 , where RE=Y, Gd, La and/or Lu; 0≦x≦0.5-y; 0<y<0.1 is used.
1. A white light-emitting device comprising:
a light-emitting diode that emits blue light; and
a phosphor that converts at least a part of the blue light into longer-wavelength radiation, wherein the phosphor is an Al-containing Tb-garnet phosphor, a Ga-containing Tb-garnet phosphor, a Ga,Al-containing Tb-garnet phosphor, or a mixture thereof, whereby the device emits white light.
2. The device of claim 1 wherein Tb is substituted from greater than 0 to 99 mol % by Y, Gd, La, and/or Lu.
3. The device of claim 1 wherein less than 50 mol % of Tb is substituted by Y, Gd, La, and/or Lu.
4. The device of claim 1 additionally comprising a yttrium aluminum garnet phosphor activated with cerium.
5. The device of claim 1 wherein the blue light from the light-emitting diode has a peak emission in the range from 430 to 470 nm.
6. The device of claim 1 wherein the emission peak of the phosphor is at approximately 550 nm.
7. The device of claim 1 wherein the white light has a color temperature below 5000 K.
8. The device of claim 1 wherein the blue light from the light-emitting diode comprises an excitation in the range from 420 to 490 nm.
9. A device that produces white light, the device comprising:
a light-emitting diode that emits blue light; and
a yellow-emitting phosphor, wherein the phosphor is a cerium-activated terbium aluminate that converts at least a part of the blue light from the light-emitting diode into yellow light, the device emitting a mix of at least blue light and yellow light to produce white light.
10. The device of claim 9 wherein at least a portion of the aluminum is substituted by gallium.
11. The device of claim 9 wherein a portion of the terbium is substituted by yttrium, gadolinium, lanthanum, and/or lutetium.
12. The device of claim 10 wherein a portion of the terbium is substituted by yttrium, gadolinium, lanthanum, and/or lutetium.
13. The device of claim 9 wherein less than 50 mol % of Tb is substituted by Y, Gd, La, and/or Lu.
14. The device of claim 10 wherein less than 50 mol % of Tb is substituted by Y, Gd, La, and/or Lu.
15. The device of claim 9 additionally comprising a yttrium aluminum garnet phosphor activated with cerium.
16. The device of claim 9 wherein the blue light from the light-emitting diode has a peak emission in the range from 430 to 470 nm.
17. The device of claim 9 wherein the emission peak of the phosphor is at approximately 550 nm.
18. The device of claim 9 wherein the white light has a color temperature below 5000 K.
19. The device of claim 9 wherein the blue light from the light-emitting diode comprises an excitation in the range from 420 to 490 nm.
20. A light-emitting device comprising:
a light-emitting diode that emits blue light; and
a phosphor that converts at least a part of the blue light into longer-wavelength radiation, wherein the phosphor is an Al-containing Tb-garnet phosphor, a Ga-containing Tb-garnet phosphor, a Ga,Al-containing Tb-garnet phosphor, or a mixture thereof.
21. The device of claim 20 wherein the blue light from the light-emitting diode has a peak emission in the range from 420 to 490 nm.
22. A device that produces light, the device comprising:
a light-emitting diode that emits blue light; and
a yellow-emitting phosphor, wherein the phosphor is a cerium-activated terbium aluminate that converts at least a part of the blue light from the light-emitting diode into yellow light.
23. The device of claim 22 wherein the blue light from the light-emitting diode has a peak emission in the range from 420 to 490 nm.