Packaged white light emitting device comprising photoluminescence layered structure

1. A white light emitting package comprising:

a solid-state excitation source for generating excitation light with a dominant wavelength in a range 440 nm to 470 nm; and

a layered photoluminescence structure comprising:

a first photoluminescence layer comprising from 75 wt % to 100 wt % of a manganese-activated fluoride photoluminescence material of the total photoluminescence material content of the first photoluminescence layer, and

a second photoluminescence layer comprising photoluminescence material for generating light with a peak emission wavelength in a range from 500 nm to 650 nm;

wherein the second photoluminescence layer is disposed on the first photoluminescence layer, and wherein the first photoluminescence layer is disposed adjacent to the solid-state excitation source.

2. The light emitting device of claim 1 , wherein the first photoluminescence layer comprises at least one of: from 90 wt % to 100 wt % of the manganese-activated fluoride photoluminescence material of the total photoluminescence material content of the first photoluminescence layer, and from 95 wt % to 100 wt % the manganese-activated fluoride photoluminescence material of the total photoluminescence material content of the first photoluminescence layer.

3. The light emitting device of claim 1 , further comprising a light transmissive layer,

wherein the light transmissive layer is disposed on the excitation source; and

wherein the first photoluminescence layer is disposed on the light transmissive layer.

4. The light emitting device of claim 3 , wherein the light transmissive layer comprises a passivation layer.

5. The light emitting device of claim 4 , wherein the passivation layer is selected from the group consisting of: a dimethyl silicone, a phenyl silicone, an epoxy, and a light transmissive inorganic oxide material.

6. The light emitting device of claim 1 , wherein the manganese-activated fluoride photoluminescence material layer comprises at least one of: K 2 SiF 6 :Mn 4+ , K 2 TiF 6 :Mn 4+ , and K 2 GeF 6 :Mn 4 .

7. The light emitting device of claim 1 , wherein the manganese-activated fluoride photoluminescence material comprises from about 30 wt % to 45 wt % of a total photoluminescence material content of the device.

8. The light emitting device of claim 1 , wherein at least one of the manganese-activated fluoride photoluminescence material or the photoluminescence material is dispersed in a light transmissive medium.

9. The light emitting device of claim 8 , wherein the light transmissive medium comprises a dimethyl silicone or phenyl silicone.

10. The light emitting device of claim 1 , wherein the photoluminescence material in the second photoluminescence layer comprises a green photoluminescence material that generates light with a peak emission wavelength in a range from 500 nm to 565 nm.

11. The light emitting device of claim 10 , wherein the second photoluminescence layer comprises from 60% to 100% of a total green photoluminescence material content of the device.

12. The light emitting device of claim 10 , wherein the green photoluminescence material comprises a cerium-activated garnet phosphor having a general composition (Lu,Y) 3-x (AlGa) 5 O 12 :Ce x or Y 3 (Al,Ga) 5 O 12 :Ce.

13. The light emitting device of claim 1 , wherein the first or second photoluminescence layer comprises an orange to red photoluminescence material for generating light with a peak emission wavelength in a range from 580 nm to 650 nm.

14. The light emitting device of claim 13 , wherein the orange to red photoluminescence material comprises a nitride-based phosphor having a general composition CaAlSiN 3 :Eu 2+ , Ca(Se, S):Eu 2+ , or (Ba, Sr) 3 SiO 5 :Eu 2+ .

15. The light emitting device of claim 1 , wherein the second photoluminescence layer comprises a mixture of a first photoluminescence material for generating light with a peak emission wavelength in a range 500 nm to 565 nm and a second photoluminescence material for generating light with a peak emission wavelength in a range 600 nm to 650 nm.

16. The light emitting device of claim 1 , wherein the manganese-activated fluoride photoluminescence material comprises less than 45 wt % of a total photoluminescence material content of the device.

17. The light emitting device of claim 1 , wherein the relative intensity of light generated by the device is at least 95% after 300 hours of operation under Wet High Temperature Operation Life test condition with a temperature of 85° C. and a relative humidity of 85%.

18. A display backlight package comprising:

a solid-state excitation source for generating excitation light with a dominant wavelength in a range 445 nm to 465 nm; and

a layered photoluminescence structure comprising:

a first photoluminescence layer comprising from 75 wt % to 100 wt % of a manganese-activated fluoride photoluminescence material of the total photoluminescence material content of the first photoluminescence layer, and

a second photoluminescence layer comprising photoluminescence material for generating light with a peak emission wavelength in a range from 520 nm to 550 nm;

wherein the second photoluminescence layer is disposed on the first photoluminescence layer, and wherein the first photoluminescence layer is disposed adjacent to the solid-state excitation source.

19. A white light emitting package comprising:

a solid-state excitation source for generating excitation light with a dominant wavelength in a range 440 nm to 470 nm; and

a layered photoluminescence structure comprising:

a first photoluminescence layer comprising from 75 wt % to 100 wt % of a manganese-activated fluoride photoluminescence material of the total photoluminescence material content of the first photoluminescence layer, and

a second photoluminescence layer comprising photoluminescence material for generating light with a peak emission wavelength in a range from 500 nm to 650 nm;

wherein the second photoluminescence layer is disposed on the first photoluminescence layer, and wherein the first photoluminescence layer is disposed adjacent to the solid-state excitation source; and

wherein the relative intensity of light generated by the device is at least 95% after 300 hours of operation under Wet High Temperature Operation Life test condition with a temperature of 85° C. and a relative humidity of 85%.

20. A white light emitting package comprising:

a solid-state excitation source for generating excitation light with a dominant wavelength in a range 440 nm to 470 nm; and

a layered photoluminescence structure comprising:

a first photoluminescence layer comprising from 75 wt % to 100 wt % of a manganese-activated fluoride photoluminescence material of the total photoluminescence material content of the first photoluminescence layer, and

a second photoluminescence layer comprising photoluminescence material for generating light with a peak emission wavelength in a range from 500 nm to 650 nm;

wherein the second photoluminescence layer is disposed on the first photoluminescence layer, and wherein the first photoluminescence layer is disposed adjacent to the solid-state excitation source; and

wherein the manganese-activated fluoride photoluminescence material comprises less than 45 wt % of a total photoluminescence material content of the device.