Red phosphors for solid state lighting
View Patent ↗A red phosphor composition in combination with a semiconductor light emitting device (e.g., VCSEL, LED, or LD), preferably a GaN based device, that emits light at a bright violet-blue light range, i.e., having a wavelength in the range of 400 nm to 600 nm, which can be further combined with green and blue phosphors. The red phosphor composition in the combination is a vanadate combined with yttrium, gadolinium and/or lanthanum and activated with trivalent Eu 3+ , Sm 3+ and Pr 3+ , or any combination thereof, with or without Tb 3+ as a co-dopant, has the general formula: Bi x Ln 1−x VO 4 :A where x=0 to 1, Ln is an element selected from the group consisting of Y, La and Gd, and A is an activator selected from Eu 3+ , Sm 3+ and Pr 3+ , or any combination thereof, with or without Tb 3+ as a co-dopant. Novel red phosphor compositions are provided when x is greater than 0 and less than 1, preferably 0.05 to 0.5.
1. A light emitting semiconductor device, comprising:
a GaN based light emitting diode that emits light having a wavelength in the range of 200 nm to 620 nm;
a red phosphor that absorbs light of a wavelength in the range of 240 nm to 550 nm and emits red light at a wavelength in the range of 580 nm to 700 nm, having the formula:
Bi x Ln 1−x VO 4 :A
where x is 0.05 to 0.5, Ln is an element selected from the group consisting of Y, La and Gd, and A is an activator selected from Eu 3+ , Sm 3+ and Pr 3+ , or any combination thereof, with or without Tb 3+ as a co-dopant;
a green phosphor; and
a blue phosphor.
2. The device of claim 1 including Tb 3+ as a co-dopant.
3. The device of claim 1 in which said green phosphor is ZnS:(Cu + ,Al 3+ ) and said blue phosphor is BaMgAl 10 O 17 :Eu 2+ .
4. A white light emitting phosphor combination, comprising:
a red phosphor having the formula:
Bi x Ln 1−x VO 4 :A
where x is greater than 0 and less than 1, Ln is an element selected from the group consisting of Y, La and Gd, and A is an activator selected from Eu 3+ , Sm 3+ , or Pr 3+ , or any combination thereof, with or without Tb 3+ as a co-dopant;
a green phosphor; and
a blue phosphor.
5. The phosphor combination of claim 4 in which said red phosphor absorbs light of a wavelength in the range of 240 nm to 550 nm and emits red light at a wavelength in the range of 580 nm to 700 nm.
6. The phosphor combination of claim 4 in which said green phosphor is ZnS:(Cu + ,Al 3+ ) and said blue phosphor is BaMgAl 10 O 17 :Eu 2+ suitable for use in a GaN based device.
7. A white light emitting phosphor combination,
a red phosphor that absorbs said light of a wavelength in the range of 240 nm to 550 nm and emits red light at a wavelength in the range of 580 nm to 700 nm, having the formula:
Bi x Ln 1−x VO 4 :A
where x is 0.05 to 0.5, Ln is an element selected from the group consisting of Y, La and Gd, and A is an activator selected from Eu 3+ , Sm 3+ and Pr 3+ , or any combination thereof, with or without Tb 3+ as a co-dopant.;
a green phosphor comprising ZnS:(Cu + ,Al 3+ ); and
a blue phosphor comprising BaMgAl 10 O 17 :Eu 2+ .
8. The phosphor combination of claim 7 in which said red phosphor includes Tb 3+ as a co-dopant.
9. A red phosphor that absorbs said light of a wavelength in the range of 240 nm to 550 nm and emits red light at a wavelength in the range of 580 nm to 700 nm , having the formula:
Bi x Ln 1−x VO 4 :A
where x is 0.05 to 0.5, Ln is an element selected from the group consisting of Y, La and Gd, and A is an activator selected from Eu 3+ , Sm 3+ and Pr 3+ , or any combination thereof, with or without Tb 3+ as a co-dopant.
10. The phosphor of claim 9 in which in which said red phosphor includes Tb 3+ as a co-dopant.
11. A light emitting device, comprising:
a semiconductor device that emits light having a wavelength in the range of 200 nm to 620 nm ; and
a red phosphor having the formula:
Bi x Ln 1−x VO 4 :A
where x is 0.05 to 0.5, Ln is an element selected from the group consisting of Y, La and Gd, and A is an activator selected from Eu 3+ , Sm 3+ and Pr 3+ , or any combination thereof, with or without Tb 3+ as a co-dopant.
12. The device of claim 11 in which the semiconductor device is a GaN based device.
13. The device of claim 12 in which the semiconductor device is a light emitting diode.
14. A light emitting device, comprising:
a semiconductor device that emits light having a wavelength in the range of 200 nm to 620 nm; and
a red phosphor comprising a vanadate combined with yttrium, gadolinium and/or lanthanum and activated with trivalent Eu 3+ , Sm 3+ or Pr 3+ , or any combination thereof, with Tb 3+ as a co-dopant.
15. A white light emitting phosphor combination, comprising:
a red phosphor comprising a vanadate combined with yttrium, gadolinium and/or lanthanum and activated with trivalent Eu 3+ , Sm 3+ and Pr 3+ , or any combination thereof, with Tb 3+ as a co-dopant;
a green phosphor; and
a blue phosphor.
16. A red phosphor that absorbs said light of a wavelength in the range of 240 nm to 550 nm and emits red light at a wavelength in the range of 580 nm to 700 nm, having the formula:
Bi x Ln 1−x VO 4 :A
where x is greater than 0 and less than 1, Ln is an element selected from the group consisting of Y, La and Gd, and A is an activator selected from Eu 3+ , Sm 3+ and Pr 3+ , or any combination thereof, with Tb 3+ as a co-dopant.
17. The phosphor of claim 16 in which x is 0.05 to 0.5.
18. A light emitting GaN based device, comprising:
a semiconductor device that emits light having a wavelength in the range of 200 nm to 620 nm;
a green phosphor and a blue phosphor; and
a red phosphor having the formula:
Bi x Ln 1−x VO 4 :A
where x is greater than 0 and less than 1, Ln is an element selected from the group consisting of Y, La and Gd, and A is an activator selected from Eu 3+ , Sm 3+ and Pr 3+ , or any combination thereof, with or without Tb 3+ as a co-dopant.
19. A light emitting GaN based device, comprising:
a semiconductor device that emits light having a wavelength in the range of 200 nm to 620 nm;
a red phosphor having the formula:
Bi x Ln 1−x VO 4 :A
where x is greater than 0 and less than 1, Ln is an element selected from the group consisting of Y, La and Gd, and A is an activator selected from Eu 3+ , Sm 3+ and Pr 3+ , or any combination thereof with or without Tb 3+ as a co-dopant;
a green phosphor having the formula: ZnS:(Cu + ,Al 3+ ); and
a blue phosphor having the formula: BaMgAl 10 O 17 :Eu 2+ .