LED phosphor comprising bow-tie shaped A

1. A lighting unit comprising a light source, configured to generate light source light and a luminescent material configured to convert at least part of the light source light into luminescent material light, wherein the light source comprises a light emitting diode (LED), and wherein the luminescent material comprises a phosphor selected from the class of

M 2 D 2 C 2-2b B b A 2 N 6 :Ln  (I)

wherein

M=one or more selected from the group consisting of divalent Ca, Sr, and Ba;

D=one or more selected from the group consisting of monovalent Li, divalent Mg, Mn, Zn, Cd, and trivalent Al and Ga;

C=one or more selected from the group consisting of monovalent Li and Cu;

B=one or more selected from the group consisting of divalent Mg, Zn, Mn and Cd;

A=one or more selected from the group consisting of tetravalent Si, Ge, Ti, and Hf;

Ln=one or more selected from the group consisting of ES and RE;

ES=one or more selected from the group consisting of divalent Eu, Sm and Yb;

RE=one or more selected from the group consisting of trivalent Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, and Tm; and

wherein 0≤b≤1.

2. The lighting unit of claim 1 , wherein M comprises one or more of Ca and Sr, wherein D comprises Mg, wherein C comprises Li and b=0, wherein A comprises Si, and wherein Ln comprises one or more of divalent Eu and trivalent Ce.

3. The lighting unit of claim 1 , wherein the phosphor comprises (M 1-x ) 2 D 2 C 2-2b B b A 2 N 6 :Eu x , wherein 0<x≤0.2.

4. The lighting unit of claim 1 , wherein the phosphor comprises (M 1-y ) 2 D 2 C 2-2b B b A 2 N 6 :Ce y , wherein 0<y≤0.2.

5. The lighting unit of claim 1 , wherein the phosphor comprises M 2 Mg 2 Li 2 Si 2 N 6 :Ln, wherein M comprises one or more of Ca and Sr.

6. The lighting unit of claim 1 , wherein the luminescent material further comprises one or more other phosphors selected from the group consisting of a divalent europium containing nitride luminescent material, a divalent europium containing oxonitride luminescent material, a trivalent cerium containing garnet and a trivalent cerium containing oxonitride, and wherein the light source is configured to generate blue light.

7. A phosphor selected from the class of

M 2 D 2 C 2-2b B b A 2 N 6 :Ln  (I)

with

M=one or more selected from the group consisting of divalent Ca, Sr, and Ba

D=one or more selected from the group consisting of monovalent Li, divalent Mg, Mn, Zn, Cd, and trivalent Al and Ga;

C=one or more selected from the group consisting of monovalent Li and Cu;

B=one or more selected from the group consisting of divalent Mg, Zn, Mn and Cd;

A=one or more selected from the group consisting of tetravalent Si, Ge, Ti, and Hf;

Ln=one or more selected from the group consisting of ES and RE;

ES=one or more selected from the group consisting of divalent Eu, Sm and Yb;

RE =one or more selected from the group consisting of trivalent Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, and Tm; and

wherein 0≤b ≤1.

8. The phosphor of claim 7 , wherein the phosphor comprises M 2 D 2 C 2-2b B b A 2 N 6 :Ln (I), wherein M comprises one or more of Ca and Sr, wherein D comprises Mg, wherein C comprises Li and b=0, wherein A comprises Si, and wherein Ln comprises one or more of divalent Eu and trivalent Ce.

9. The phosphor of claim 7 , wherein the phosphor comprises (M 1-x ) 2 D 2 C 2-2b B b A 2 N 6 :Eu x , wherein 0 <x ≤0.2.

10. The phosphor of claim 7 , wherein the phosphor comprises (M 1-y ) 2 D 2 C 2-2b B b A 2 N 6 :Ce y , wherein 0 <y ≤0.2.

11. The phosphor of claim 7 , wherein the phosphor comprises M 2 Mg 2 Li 2 Si 2 N 6 :Ln, wherein M comprises one or more of Ca and Sr.

12. The phosphor of claim 7 , wherein the phosphor comprises phosphor particles having a coating, wherein the coating comprises one or more coating selected from the group consisting of an AlPO 4 coating, an Al 2 O 3 coating and a SiO 2 coating.

13. A method for making a phosphor, the method comprising steps of:

combining a selection of starting materials to form the phosphor in the class of,

M 2 D 2 C 2-2b B b A 2 N 6 :Ln  (I)

wherein

M=one or more selected from the group consisting of divalent Ca, Sr, and Ba

D=one or more selected from the group consisting of monovalent Li, divalent Mg, Mn, Zn, Cd, and trivalent Al and Ga;

C=one or more selected from the group consisting of monovalent Li and Cu;

B=one or more selected from the group consisting of divalent Mg, Zn, Mn and Cd;

A=one or more selected from the group consisting of tetravalent Si, Ge, Ti, and Hf;

Ln=one or more selected from the group consisting of ES and RE;

ES=one or more selected from the group consisting of divalent Eu, Sm and Yb;

RE=one or more selected from the group consisting of trivalent Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, and Tm; and

wherein 0 ≤b ≤1; and

heating the starting materials at a temperature in a range of about 800° C. to about 1300° C.

14. The method of claim 13 , wherein Ln comprises one or more of Eu and Ce, and wherein the heating is performed in a reducing atmosphere.

15. A backlighting unit of an LCD display device comprising the lighting unit of claim 1 .

16. A projection system comprising the lighting unit of claim 1 .

17. A self-lit display system comprising the lighting unit of claim 1 .

18. A pixelated display system comprising the lighting unit of claim 1 .

19. A segmented display system comprising the lighting unit of claim 1 .

20. A medical lighting system comprising the lighting unit of claim 1 .