Silicon carbidonitride based phosphors and lighting devices using the same
View Patent ↗Disclosed herein are novel families of silicon carbidonitride phosphor compositions. In certain embodiments, optimal ranges of carbon content have been identified which provide excellent luminescence and thermal stability characteristics.
1. A composition comprising a phosphor having the formula
Sr 2 Si 5 N 8−[(4x/3)+z] C x O 3z/2 :A
wherein 0<x≦5.0; wherein 0.06≦z≦0.1; wherein ((4x/3)+z)<8; wherein x≠3z/2; and wherein A comprises a luminescence activator doped in the host crystal of the phosphor.
2. A composition comprising a phosphor having the formula
M(II) 2 Si 5 N 8−[(4x/3)+z] C x O 3z/2 :A
wherein 1.0≦x≦2.0; wherein 0≦z≦0.1; wherein ((4x/3)+z) <8; wherein x≠3z/2, wherein M(II) comprises at least one divalent cation; and, wherein A comprises a luminescence activator doped in the host crystal of the phosphor.
3. A composition comprising a phosphor having the formula
M(II) 2−w M(I) 2w Si 5 N 8−[(4x/3)+z] C x O 3z/2 :A
wherein 0.5≦x≦3.0; wherein 0≦z≦0.1; wherein 0.05≦w≦0.5; wherein ((4x/3)+z)<8;
wherein x≠3z/2; wherein M(II) comprises at least one divalent cation; wherein M(I) comprises at least one monovalent cation; and, wherein A comprises a luminescence activator doped in the host crystal of the phosphor.
4. A light emitting device comprising:
a light source emitting a first luminescence spectrum; and
a phosphor composition, which, when irradiated with light from the light source, emits light having a second luminescence spectrum;
wherein the phosphor composition comprises at, least one phosphor having a formula selected from the group consisting of:
(a) Sr 2 Si 5 N 8−[(4x/3)+z] C x O 3z/2 :A, wherein 0<x≦5.0; wherein 0.06≦z≦0.1; wherein ((4x/3)+z)<8; and, wherein x≠3z/2;
(b) M(II) 2 Si 5 N 8−[(4x/3)+z] C x O 3z/2 :A, wherein 1.0≦x≦2.0; wherein 0≦z≦0.1; wherein ((4x/3)+z)<8; and, wherein x≠3Z/2;
(c) M(II) 2−w M(I) 2w Si 5 N 8−[(4x/3)+z] C x O 3z/2: A, wherein 0.5≦x≦3.0; wherein 0≦z≦0.1; wherein 0.05≦w≦0.5; wherein ((4x/3)+z)<8; and, wherein x≠3z/2;
wherein M(II) comprises at least one divalent cation; wherein M(I) comprises at least one monovalent cation; wherein C comprises a tetravalent anion of carbon; and, wherein A comprises, a luminescence activator doped in the host crystal.
5. The composition of claim 1 , wherein A comprises a luminescence activator selected from the group consisting of Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Mn, Bi, and Sb.
6. The composition of claim 1 , wherein A is Eu.
7. The composition of claim 1 , wherein A is doped in the host crystal of the phosphor at a concentration level of from about 0.001 mol % to about 20 mol % relative to the mole amount of Sr.
8. The composition of claim 1 , further comprising one or more additional phosphors.
9. The composition of claim 1 , wherein the phosphor comprises a crystal of an orthorhombic or a monoclinic system.
10. The composition of claim 2 , wherein M(II) comprises at least one divalent cation selected from the group consisting of Be, Mg, Ca, Sr, Ba, Cu, Co, Ni, Pd, Zn, and Cd.
11. The composition of claim 2 , wherein M(II) comprises at least one divalent cation selected from the group consisting of Ca, Sr, and Ba.
12. The composition of claim 10 , wherein M(II) comprises two or more divalent cations.
13. The composition of claim 2 , wherein A comprises a luminescence activator selected from the group consisting of Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Mn, Bi, and Sb.
14. The composition of claim 2 , wherein A is Eu.
15. The composition of claim 2 , wherein A is doped in the host crystal of the phosphor at a concentration level of from about 0.001 mol % to about 20 mol % relative to the mole amount of M(II).
16. The composition of claim 2 , further comprising one or more additional phosphors.
17. The composition of claim 2 , wherein the phosphor comprises a crystal of an orthorhombic or a monoclinic system.
18. The composition of claim 3 , wherein M(II) comprises at least one divalent cation selected from the group consisting of Be, Mg, Ca, Sr, Ba, Cu, Co, Ni, Pd, Zn, and Cd.
19. The composition of claim 3 , wherein M(II) comprises at least one divalent cation selected from the group consisting of Ca, Sr, and Ba.
20. The composition of claim 18 , wherein M(II) comprises two or more divalent cations.
21. The composition of claim 3 , wherein M(I) comprises at least one monovalent cation selected from the group consisting of Li, Na, K, Rb, Cu, Ag and Au.
22. The composition of claim 3 , wherein M(I) comprises at least one monovalent cation selected from the group consisting of Li, Na, and K.
23. The composition of claim 21 , wherein M(I) comprises two or more monovalent cations.
24. The composition of claim 3 , wherein A comprises a luminescence activator selected from the group consisting of Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Mn, Bi, and Sb.
25. The composition of claim 3 , wherein A is Eu.
26. The composition of claim 3 , wherein A is doped in the host crystal of the phosphor at a concentration level of from about 0.001 mol % to about 20 mol % relative to the total mole amount of M(II) and M(I).
27. The composition of claim 3 , further comprising one or more additional phosphors.
28. The composition of claim 3 , wherein the phosphor comprises a crystal of an orthorhombic or a monoclinic system.
29. The light emitting device of claim 4 , wherein:
M(II) comprises at least one divalent cation selected from the group consisting of Be, Mg, Ca, Sr, Bo, Cu, Co, Ni, Pd, Zn, and Cd;
M(I) comprises at least one monovalent cation selected from the group consisting of Li, Na, K, Rb, Cu, Ag and Au;
C comprises a tetravalent anion of carbon; and,
A comprises at least one luminescence activator selected from the group consisting of Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Mn, Bi, and Sb.
30. The light emitting device of claim 4 , wherein the first luminescence spectrum has a peak in wavelength range from about 250 nm to about 700 nm.
31. The light emitting device of claim 4 , wherein the first luminescence spectrum has a peak in wavelength range from about 400 nm to about 550 nm.
32. The light emitting device of claim 4 , wherein the light source is a light emitting diode or a laser diode.
33. The light emitting device of claim 4 , further comprising one or more additional phosphors.
34. The light emitting device of claim claim 4 , wherein the additional phosphor emits red, yellow, orange, green, or blue light when excited by a light source.
35. The light emitting device of claim claim 4 , further comprising a second phosphor having a formula selected from the group consisting of: Ca 1−x Sr x Ga 2 S 4 :Eu 2+ (0≦x≦1), Ca 1−x−y−z Mg x Sr y Ba z SiO 4 :Eu 2+ (0≦x≦1, 0≦y≦1, 0≦z≦1, x+y+z≦1), BaMgAl 10 O 17 :Eu 2+ ,Mn 2+ , MYSi 4 N 7 :Eu 2+ (M=Ca, Sr, Ba), β-sialon:Eu 2+ , MSi 2 O 2 N 2 :Eu 2+ (M=Mg, Ca, Sr, Ba), Ba 3 Si 6 O 12 N 2 :Eu 2+ , M 2 Si 5 N 8 :Ce 3+ (M=Ca, Sr, Ba), Y 2 Si 4 N 6 C:Ce 3+ , α-sialon:Yb 2+ , (MSiO 3 ) m ·(SiO 2 ) n :Eu 2+ , X (M=Mg, Ca, Sr, Ba; X=F, Cl, Br, I), where m is 1 or 0, and either (i) n>3 if m=1 or (ii) n=1 if m=0, MAl 2 O 4 :Eu 2+ (M=Mg, Ca, Sr, Ba), BaMgAl 10 O 17 :Eu 2+ , Y 3 Al 5 O 12 :Ce 3+ , and α-sialon:Eu 2+ .
36. The light emitting device of claim 4 , further comprising a second phosphor having a formula selected from the group consisting of:
(a) M(II) a Si b O c N d C e :A, wherein 6<a<8, 8<b<14, 13<c<17, 5<d<9, 0<e<2;
(b) M(II) 7 Al 12−x−y Si x+y O 25−x N x−y C y :A, wherein 0<x≦12, 0<y<x, and 0<x+y≦12;
(c) M(II) 7 M(III) 12−x−y Si x+y O 25−x N x−y C y :A, wherein 0<x≦12, 0<x+y≦12, and 0<y<x;
(d) M(II) 7 M(III) 12−x−y Si x+y O 25−x±3δ/2 N x∓δ−y C y :A, wherein 0<x<12, 0≦y<x, 0<x+y≦12, 0<δ≦3, and δ<x+y;
(e) M(II) 7 M(III) 12−x−y Si x+y O 25−x±δ/2 N x∓δ−y C y±δ/2 :A, wherein 0<x<12, 0≦y<x, 0<x+y≦12, 0<δ≦3, and δ<x+y;
(f) M(II) 7−y M(I) y M(III) 12−x−y−z Si x+y+z O 25−x±3δ/2 N x∓δ−z C z :A, wherein 0<x<12, 0≦y<x, 0<z<x, 0<x+y+z≦12, z<x+δ, and 0<δ≦3;
(g) M(II) 7−y M(I) y M(III) 12−x−y−z Si x+y+z O 25−x±δ/2 N x∓δ−z C z±δ/2 :A, wherein 0<x<12, 0≦y<x, 0<z<x, 0<x+y+z≦12, z<x+δ, and 0<δ≦3;
(h) M(II) 7−y M(I) y M(III) 12−x−y−z Si x+y+z O 25−x±3δ/2−v/2 N x∓δ−z C z H v :A, wherein 0<x<12, 0≦y<1, 0<z<x, z<x+δ, 0<δ≦3, 0≦v<1, and 0<x+y+z≦12; and
(i) M(II) 7−y M(I) y M(III) 12−x−y−z Si x+y+z O 25−x±δ/2−v/2 N x∓δ−z C z±δ/2 H v :A, wherein 0<x<12, 0≦y<1, 0<z<x, z<x+δ, 0<δ≦3, 0≦v<1, and 0<x+y+z≦12;
wherein:
M(II) comprises at least one divalent cation;
M(I) comprises at least one monovalent cation;
M(III) comprises at least one trivalent cation;
H comprises at least one monovalent anion; and
A comprises a luminescence activator doped in the host crystal.
37. The light emitting device of claim 4 , further comprising at least two additional phosphors,
38. The light emitting device of claim 4 , further comprising at least one additional phosphor that emits light having a peak in wavelength range from about 350 nm to about 700 nm.
39. The light emitting device of claim 4 , further comprising at least one additional phosphor that emits light having a peak in wavelength range from about 480 nm to about 640 nm.
40. The light emitting device of claim 4 , further comprising at least one additional phosphor that emits light having a peak in wavelength range from about 520 nm to about 600 nm.
41. The light emitting device of claim 4 , wherein the device emits white light.
42. The light emitting device of claim 4 , wherein the device emits cool white light.
43. The light emitting device of claim 4 , wherein the device emits warm white light.
44. The light emitting device of claim 4 , wherein the device emits light having a peak in wavelength range from about 400 nm to about 600 nm.
45. The light emitting device of claim 4 , wherein the device emits light having a peak in wavelength range from about 520 nm to about 600 nm.
46. The light emitting device of claim 4 , wherein the device emits light having a peak in wavelength range from about 380 nm to about 750 nm.
47. The light emitting device of claim 4 , wherein the device emits light having, a peak in wavelength range from about 400 nm to about 700 nm.