Nitridosilicate phosphor tunable light-emitting diodes by using UV and blue chips

1. A method, comprising:

attaching a first light-emitting diode (LED) having indium gallium nitride (InGaN) to a support substrate;

attaching a second LED having aluminum gallium nitride (AlGaN) to the support substrate; and

disposing a luminescent material on the first LED and the second LED, wherein the luminescent material includes a strontium silicon nitride (SrSi 6 N 8 ) doped by one of cerium (Ce 3+ ) and cerium, lithium (Ce 3+ , Li + ) in a manner so that the doped stronium silicon nitride is formulated as one of: Sr 1-x Si 6 N 8 :Ce 3+ x and Sr 1-2x Si 6 N 8 :Ce 3+ x , Li + x , wherein x ranges between about 0.05 and about 0.5.

2. The method of claim 1 , wherein the disposing the luminescent material includes:

dispersing the luminescent material into a material selected from one of silicone and epoxy; and

disposing the material with the luminescent material on the first and second LEDs.

3. The method of claim 1 , further comprising forming the luminescent material by:

mixing stoichiometrically powdered strontium nitride (Sr 3 N 2 ), silicon nitride (Si 3 N 4 ), and cerium oxide (CeO 2 ), thereby forming a mixture; and

sintering the mixture under a high pressure and a high temperature, thereby forming a luminescent material having a strontium silicon nitride (SrSi 6 N 8 ) doped by cerium (Ce 3+ ).

4. The method of claim 1 , further comprising forming one of:

a reflective feature approximate the first and second LEDs; and

a lens configured on and aligned with the first and second LEDs.

5. A radiation device comprising:

a first light emitting diode (LED) operable to emit light having a first central wavelength;

a second LED configured adjacent the first LED and operable to emit light having a second central wavelength substantially less than the first central wavelength; and

a luminescent material disposed on the first LED and the second LED, wherein the luminescent material includes a strontium silicon nitride (SrSi 6 N 8 ) doped by one of: cerium (Ce 3+ ) and cerium, lithium (Ce 3+ , Li + ) in a manner so that the doped stronium silicon nitride is formulated as one of: Sr 1-x Si 6 N 8 :Ce 3+ x and Sr 1-2x Si 6 N 8 :Ce 3+ x , Li + x , wherein x ranges between about 0.05 and about 0.5.

6. The radiation device of claim 1 , wherein the first LED includes an emission spectrum having a wavelength range from 400 nm to 500 nm.

7. The radiation device of claim 1 , wherein the first LED includes indium gallium nitride (InGaN).

8. The radiation device of claim 1 , wherein the second LED includes an emission spectrum having a wavelength range from 360 nm to 430 nm.

9. The radiation device of claim 1 , wherein the second LED includes aluminum gallium nitride (AlGaN).

10. The radiation device of claim 1 , wherein the first and second LEDs are attached to a support substrate by one of silver paste and soldering.

11. The radiation device of claim 1 , wherein each of the first and second LEDs includes a semiconductor substrate selected from the group consisting of sapphire, silicon carbide, gallium nitride, and silicon.

12. The radiation device of claim 1 , wherein the luminescent material is powdered and dispersed in a material selected from the group consisting of silicone and epoxy.

13. The radiation device of claim 1 , further including a reflective surface configured adjacent the first and second LEDs for emission efficiency.

14. The radiation device of claim 1 , further including a lens configured on and aligned with the first and second LEDs.

15. The radiation device of claim 1 , wherein the luminescent material emits red light excited by the first LED and emits bluish green light to yellow light excited by the second LED.

16. The radiation device of claim 1 , wherein the luminescent material includes:

an emission spectrum having a wavelength range from 550 nm to 800 nm when excited by the first LED; and

an emission spectrum having a wavelength range from 400 nm to 600 nm when excited by the second LED.

17. A radiation device comprising:

a first light emitting diode (LED) operable to emit blue light;

a second LED configured adjacent the first LED and operable to emit ultraviolet (UV) light;

a rare earth (RE) element doped nitridosilicate phosphor formulated as M x-z Si y N 2/3x+11/9y :RE z ; where

M is one of calcium (Ca), strontium (Sr), and barium (Ba);

x, y, and z satisfy 0<z<x<y; and

RE is one of cerium (Ce 3+ ) and cerium, lithium (Ce 3+ , Li + ), wherein when M is strontium, the rare earth element doped nitridosilicate phosphor is formulated as one of: Sr 1-x , Si 6 N 8 :Ce 3+ x and Sr 1-2x Si 6 N 8 :Ce 3+ x , Li + x , wherein x ranging between about 0.05 and about 0.5, and wherein the rare earth element doped nitridosilicate phosphor is disposed on the first and second LEDs; and

a lens covering the first and second LEDs and the rare earth element doped nitrodosilicate phosphor.

18. The radiation device of claim 17 , wherein the rare earth element doped nitridosilicate phosphor includes:

a strontium silicon nitride (SrSi 6 N 8 ) doped by one of a first dopant having cerium (Ce 3+ ), formulated as Sr 1-x Si 6 N 8 :Ce 3+ x and a second dopant having cerium and lithium (Ce 3+ , Li + ), formulated as Sr 1-2x Si 6 N 8 :Ce 3+ x , Li 3+ x , wherein x ranges between about 0.05 and about 0.5.

19. The radiation device of claim 17 , wherein:

the first LED includes indium gallium nitride (InGaN);

the second LED includes aluminum gallium nitride (AlGaN); and

the rare earth element doped nitridosilicate phosphor is dispersed in one of silicone and epoxy.