Cerium and europium doped phosphor compositions and light emitting devices including the same

1. A light emitting device, comprising:

a light emitting element configured to emit light at a wavelength in a range of about 380 nm to about 470 nm; and

a phosphor configured to absorb at least some of the light emitted from the light emitting element, wherein the phosphor emits light having a maximum emission wavelength in a range of about 500 to about 700 nm;

wherein the full width at half maximum of the light emitted from the phosphor is in a range of about 120 to about 200 nm; and

wherein the phosphor comprises a compound having a CaAlSiN 3 -type crystal structure that is co-doped with cerium and europium;

wherein the phosphor comprises a single crystal phosphor preform attached to the light emitting element, the single crystal phosphor preform comprising a single crystal of a material having a compound of Formula I:

A a B b C c D d E e   (I)

wherein A comprises one or more elements selected from the group consisting of Ca, Sr, Ba, Mg, Y, Hf, the lanthanide elements and the other alkaline earth metals;

B comprises Eu and Ce;

C comprises one or more tetrahedrally-coordinated trivalent elements;

D comprises one or more tetrahedrally-coordinated tetravalent elements;

E comprises one or more elements selected from the group consisting of N, O, F, C, S, Cl, Br and I, wherein a+b=1 and c+d=2,and e is in a range of 2.5 to 3.5.

2. The light emitting device of claim 1 , wherein the conversion efficiency of the phosphor is in a range of about 60 to about 100%.

3. The light emitting device of claim 1 , wherein a, b, c, and d satisfy the following requirements:

a is in a range of 0.7 to 0.99;

b is in a range of 0.01 to 0.3;

c is in a range of 0.5 to 1.5;

d is in a range of 0.5 to 1.5.

4. The light emitting device of claim 1 , wherein b is in a range of 0.05 to 0.2.

5. The light emitting device of claim 1 , wherein A comprises one or more of elements selected from the group consisting of Mg, Ba, Sr and Ca.

6. The light emitting device of claim 5 , wherein A comprises Ca.

7. The light emitting device of claim 1 , wherein C comprises one or more elements selected from the group consisting of Al, B, Ga, P, In, Sc, Y, Gd, and Lu.

8. The light emitting device of claim 7 , wherein C comprises Al.

9. The light emitting device of claim 1 , wherein D comprises one or more elements selected from the group consisting of Si, Ge, Sn, Ti, Zr and Hf.

10. The light emitting device of claim 9 , wherein D comprises Si.

11. The light emitting device of claim 1 , wherein E comprises N, C, S, Cl, Br, I and/or F.

12. The light emitting device of claim 11 , wherein E comprises N.

13. The light emitting device of claim 1 , wherein A comprises Sr and Ca, wherein χ(Sr)+χ(Ca)=1.

14. The light emitting device of claim 1 , wherein C comprises Al and D comprises Si, wherein c+d =2.

15. The light emitting device of Claim 1 , wherein E comprises O and N, and χ(O)+χ(N)=3.

16. The light emitting device of claim 1 , wherein cerium and europium are together present in the compound at concentration in a range of about 0.1% to about 20% by weight.

17. The light emitting device of claim 1 , wherein the maximum emission wavelength of the phosphor occurs when the phosphor is irradiated with radiation in a range of about 380 nm to about 480 nm.

18. The light emitting device of claim 17 , wherein the full width at half maximum is less than about 200 nm.

19. The light emitting device of claim 10 , further comprising an adhesion layer between the phosphor preform and the light emitting element.