Red line emitting phosphors for use in LED applications

• US 20070205712A1
• Filed: 02/13/2007
• Published: 09/06/2007
• Est. Priority Date: 02/02/2005
• Status: Active Grant

• Current Assignee: General Electric Company
• Original Assignee: Lumination LLC
• Inventors: Srivastava, Alok, Radkov, Emil, Setlur, Anant, Grigorov, Ljudmil
• Granted Patent: US 7,648,649 B2
• Time in Patent Office: Days
• US Class Current: 313/503
• CPC Class Codes: C09K 11/0838 Aluminates; Silicates
• CPC Class Codes: C09K 11/584 with zinc or cadmium
• CPC Class Codes: C09K 11/612 with zinc or cadmium
• CPC Class Codes: C09K 11/616 with alkali or alkaline earth metals
• CPC Class Codes: C09K 11/628 with alkali or alkaline earth metals
• CPC Class Codes: C09K 11/643 with alkaline earth metals
• CPC Class Codes: C09K 11/644 Halogenides C09K11/641 takes precedence
• CPC Class Codes: C09K 11/645 with alkali or alkaline earth metals
• CPC Class Codes: C09K 11/675 with alkali or alkaline earth metals
• CPC Class Codes: C09K 11/77342 Silicates
• CPC Class Codes: C09K 11/7737 Phosphates
• CPC Class Codes: C09K 11/7739 with halogens
• CPC Class Codes: C09K 11/7768 with alkaline earth metals
• CPC Class Codes: C09K 11/7774 Aluminates
• CPC Class Codes: C09K 11/7778 with alkaline earth metals
• CPC Class Codes: C09K 11/778 Borates
• CPC Class Codes: C09K 11/7786 with alkaline earth metals
• CPC Class Codes: C09K 11/7787 Oxides C09K11/7785 takes precedence
• CPC Class Codes: C09K 11/7794 Vanadates; Chromates; Molybdates; Tungstates
• CPC Class Codes: C09K 11/7797 Borates
• CPC Class Codes: H01L 2224/48091 : Arched
• CPC Class Codes: H01L 2224/48247 : connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2924/00014 : the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 33/502 : Wavelength conversion materials

Abstract

Light emitting devices including backlights having a light source and a phosphor material including a complex fluoride phosphor activated with Mn⁴⁺ which may include at least one of (A) A₂[MF₅]:Mn⁴⁺; where A is selected from Li, Na, K, Rb, Cs, NH₄, and combinations thereof; and where M is selected from Al, Ga, In, or combinations thereof; (B) A₃[MF₆]:Mn⁴⁺, where A is selected from Li, Na, K, Rb, Cs, NH₄, and combinations thereof; and where M is selected from Al, Ga, In, or combinations thereof; (C) Zn₂[MF₇]:Mn⁴⁺, where M is selected from Al, Ga, In, or combinations thereof; and (D) A[In₂F₇]:Mn⁴⁺ where A is selected from Li, Na, K, Rb, Cs, NH₄, or combinations thereof.

Claims

1. A lighting apparatus for emitting white light comprising:

a semiconductor light source; and

a phosphor material radiationally coupled to the light source, wherein said phosphor material comprises at least one phosphor selected from the group consisting of;

(A) A₂[MF₅];

Mn⁴⁺, where A is selected from Li, Na, K, Rb, Cs, NH₄, and combinations thereof; and

where M is selected from Al, Ga, In, or combinations thereof;

(B) A₃[MF₆];

Mn⁴⁺, where A is selected from Li, Na, K, Rb, Cs, NH₄, and combinations thereof; and

where M is selected from Al, Ga, In, or combinations thereof;

(C) Zn₂[MF₇];

Mn⁴⁺, where M is selected from Al, Ga, In, or combinations thereof; and

(D) A[In₂F₇];

Mn⁴⁺ where A is selected from Li, Na, K, Rb, Cs, NH₄, or combinations thereof.

2. The lighting apparatus of claim 1, wherein the light source is a semiconductor light emitting diode (LED) emitting radiation having a wavelength in the range of from about 370 to about 500 nm.

3. The lighting apparatus of claim 1, wherein said semiconductor light source comprises a nitride compound semiconductor represented by the formula In_iGa_jAl_kN, where 0≦

i;

0≦

j, 0≦

k, and i+j+k=1.

4. The lighting apparatus of claim 1, wherein the light source is an organic emissive structure.

5. The lighting apparatus of claim 1, wherein the phosphor material is coated on the surface of the light source.

6. The lighting apparatus of claim 1, further comprising an encapsulant surrounding the light source and the phosphor material.

7. The lighting apparatus of claim 1, wherein the phosphor material is dispersed in the encapsulant.

8. The lighting apparatus of claim 1, further comprising a reflector cup.

9. The lighting apparatus of claim 1, wherein said phosphor material further comprises one or more additional phosphors.

10. The lighting apparatus of claim 9, wherein said one or more additional phosphors has an emission maximum in the range of 430 to 500 nm.

11. The lighting apparatus of claim 9, wherein said one or more additional phosphors has an emission maximum in the range of 500 to 610 nm.

12. The lighting apparatus of claim 11, wherein said one or more additional phosphors is one or more of a garnet activated with Ce³⁺ or an alkaline earth orthosilicate activated with Eu²⁺.

13. The lighting apparatus of claim 9, wherein said one or more additional phosphors are selected from the group including:

(Ba,Sr,Ca)₅(PO₄)₃(Cl,F,Br,OH);

Eu²⁺,Mn²⁺;

(Ba,Sr,Ca)BPO₅;

Eu²⁺,Mn²⁺;

Sr,Ca)₁₀(PO₄)₆*ν

B₂O₃;

Eu²⁺ (wherein 0<

ν

≦

1);

Sr₂Si₃O₈*2SrCl₂;

Eu²⁺;

(Ca,Sr,Ba)₃MgSi₂O₈;

Eu²⁺,Mn²⁺;

BaAl₈O₁₃;

Eu²⁺;

2SrO*0.84P₂O₅*0.16B₂O₃;

Eu²⁺;

(Ba,Sr,Ca)MgAl₁₀O₁₇;

Eu²⁺,Mn²⁺;

(Ba,Sr,Ca)Al₂O₄;

Eu²⁺;

(Y,Gd,Lu,Sc,La)BO₃;

Ce³⁺,Tb³⁺;

ZnS;

Cu⁺,Cl⁻

;

ZnS;

Cu⁺,Al³⁺;

ZnS;

Ag⁺,Cl⁻

;

ZnS;

Ag⁺,Al³⁺;

(Ba,Sr,Ca)₂Si<sub>1−

ξ</sub>

O<sub>4−

2ξ</sub>

;

Eu²⁺ (wherein 0≦

ξ

≦

0.2) (Ba,Sr,Ca)₂(Mg,Zn)Si₂O₇;

Eu²⁺;

(Sr,Ca,Ba)(Al,Ga,In)₂S₄;

Eu²⁺;

(Y,Gd,Tb,La,Sm,Pr,Lu)₃(Sc,Al,Ga)<sub>5−

α</sub>

O<sub>12−

3/2α</sub>

;

Ce³⁺ (wherein 0≦

α

≦

0.5) (Ca,Sr)₈(Mg,Zn)(SiO₄)₄Cl₂;

Eu²⁺,Mn²⁺;

Na₂Gd₂B₂O₇;

Ce³⁺,Tb³⁺;

(Sr,Ca,Ba,Mg,Zn)₂P₂O₇;

Eu²⁺,Mn²⁺;

(Gd,Y,Lu,La)₂O<sub>3;

Eu</sub>³⁺,Bi³⁺;

(Gd,Y,Lu,La)₂O₂S;

Eu³⁺,Bi³⁺;

(Gd,Y,Lu,La)VO₄;

Eu³⁺,Bi³⁺;

(Ca,Sr)S;

Eu²⁺,Ce³⁺;

SrY₂S₄;

Eu²⁺;

CaLa₂S₄;

Ce³⁺;

(Ba,Sr,Ca)MgP₂O₇;

Eu²⁺,Mn²⁺;

(Y,Lu)₂WO₆;

Eu³⁺,Mo⁶⁺;

(Ba,Sr,Ca)_β

Si_γ

N_μ

;

Eu²⁺ (wherein 2β

+4γ

=3μ

);

Ca₃(SiO₄)Cl₂;

Eu²⁺;

(Lu,Sc,Y,Tb)<sub>2−

u−

v</sub>Ce_vCa_1+uLi_wMg<sub>2−

w</sub>P_w(Si,Ge)<sub>3−

w</sub>O<sub>12−

u/2</sub> (where −

0.5≦

u≦

1;

0<

v≦

0.1; and

0≦

w≦

0.2);

(Y,Lu,Gd)<sub>2−

φ</sub>

Ca_φ

Si₄N_6+φ

C_1-φ

;

Ce³⁺, (wherein 0≦

φ

≦

0.5);

(Lu,Ca,Li,Mg,Y)alpha-SiAlON doped with Eu²⁺ and/or Ce³⁺;

(Ca,Sr,Ba)SiO₂N₂;

Eu²⁺,Ce³⁺;

3.5MgO*0.5MgF₂*GeO₂;

Mn⁴⁺;

Ca<sub>1−

c−

f</sub>Ce_cEu_fAl_1+cSi<sub>1−

c</sub>N₃, (where 0<

c≦

0.2, 0≦

f≦

0.2);

Ca<sub>1−

h−

r</sub>Ce_hEu_rAl<sub>1−

h</sub>(Mg,Zn)_hSiN₃, (where 0<

h≦

0.2, 0≦

r≦

0.2);

Ca<sub>1−

2s−

t</sub>Ce_s(Li,Na)_sEu_tAlSiN₃, (where 0≦

s≦

0.2, 0≦

f≦

0.2, s+t>

0); and

Ca<sub>1−

σ

−

χ

−

φ</sub>

Ce_σ

(Li,Na)_χ

Eu_φ

Al<sub>1+σ

χ</sub>

Si<sub>1−

σ

+χ</sub>

N₃, (where 0≦

σ

≦

0.2, 0<

χ

≦

0.4, 0≦

φ

≦

0.2).

14. The lighting apparatus of claim 9, where said lighting apparatus produces white light.

15. The lighting apparatus of claim 14, where said white light has a CCT of less than 4500K.

16. The lighting apparatus of claim 14, where said white light has a general CRI (R_a) greater than 80.

17. The lighting apparatus of claim 14, where said white light has a general CRI greater than 90.

18. The lighting apparatus of claim 14, where said white light has a LER greater than 330 Im/W_opt.

19. The lighting apparatus of claim 14, where said white light has a color point lying on or substantially on the Planckian locus.

20. The lighting apparatus of claim 19, where a color point of said white light is within 0.01 from the Planckian locus in the vertical direction on the CIE 1931 chromaticity diagram.

21. A phosphor material comprising at least one phosphor selected from the group consisting of:

(A) A₂[MF₅];

Mn⁴⁺, where A is selected from Li, Na, K, Rb, Cs, NH₄, and combinations thereof; and

where M is selected from Al, Ga, In, or combinations thereof;

(B) A₃[MF₆];

Mn⁴⁺, where A is selected from Li, Na, K, Rb, Cs, NH₄, and combinations thereof; and

where M is selected from Al, Ga, In, or combinations thereof;

(C) Zn₂[MF₇];

Mn⁴⁺, where M is selected from Al, Ga, In, or combinations thereof; and

(D) A[In₂F₇];

Mn⁴⁺ where A is selected from Li, Na, K, Rb, Cs, NH₄, or combinations thereof.

22. A phosphor blend comprising at least one phosphor material selected from the group consisting of (A)-(D), and at least one additional phosphor:

(A) A₂[MF₅];

Mn⁴⁺, where A is selected from Li, Na, K, Rb, Cs, NH₄, and combinations thereof; and

where M is selected from Al, Ga, In, or combinations thereof;

(B) A₃[MF₆];

Mn⁴⁺, where A is selected from Li, Na, K, Rb, Cs, NH₄, and combinations thereof; and

where M is selected from Al, Ga, In, or combinations thereof;

(C) Zn₂[MF₇];

Mn⁴⁺, where M is selected from Al, Ga, In, or combinations thereof; and

(D) A[In₂F₇];

Mn⁴⁺ where A is selected from Li, Na, K, Rb, Cs, NH₄, or combinations thereof.

23. A backlight device comprising a red line-emitting complex fluoride phosphor material activated with Mn⁴⁺ having a peak emission wavelength between 610 and 650 nm;

a green emitting phosphor having a peak emission wavelength between 510 and 550 nm; and

either a) a blue LED chip having a peak emission wavelength between 440 and 480 nm, or b) a blue emitting phosphor having a peak emission wavelength between 440 and 480 nm and a violet to near-UV emitting LED chip having a peak emission wavelength from about 370 nm to about 440 nm.

24. The backlight device according to claim 23, wherein said phosphor material activated with Mn⁴⁺ comprises a complex fluoride with coordination number of 6.

25. The backlight device according to claim 24, wherein said phosphor material activated with Mn⁴⁺ comprises A₂[MF₆]:

Mn⁴⁺, where A is selected from Li, Na, K, Rb, Cs, NH₄, or combinations thereof; and

where M is selected from Ge, Si, Sn, Ti, Zr, or combinations thereof.

26. The backlight device according to claim 23, wherein said device has a CCT greater than 5000K and an LER greater than 280 Im/W_opt.

27. The backlight emitting device according to claim 23, wherein said green emitting phosphor comprises an alkaline earth thiogallate, thioaluminate or a solid solution thereof activated with Eu²⁺.

28. The backlight emitting device according to claim 27, wherein said green emitting phosphor comprises strontium thiogallate activated with Eu²⁺.

29. The backlight device according to claim 23, wherein said device has a gamut greater than 70% that of the NTSC in the CIE 1931 x, y diagram.

30. The backlight device according to claim 23, wherein said device has a gamut greater than 90% that of the NTSC in the CIE 1931 x, y diagram.