Solid-state white light generating lighting arrangements including photoluminescence wavelength conversion components

1. A white light photoluminescence wavelength conversion component comprising:

at least one blue light excitable green to yellow light emitting yttrium aluminum garnet type phosphor which, when excited, emits green to yellow light having a peak wavelength in a range 510 nm to 570 nm and

at least one blue light excitable orange to red light emitting organic fluorescent dye which, when excited, emits orange to red light having a peak wavelength in a range 585 nm to 670 nm;

wherein organic fluorescent dye comprises less than 0.01% by weight of total photoluminescence material formed from a mixture of the at least one blue light excitable orange to red light emitting organic fluorescent dye and the at least one blue light excitable green to yellow light emitting yttrium aluminum garnet type phosphor.

2. The white light photoluminescence wavelength conversion component of claim 1 , wherein the at least one yttrium aluminum garnet type phosphor, when excited, emits green light having a peak wavelength in a range 525 nm to 542 nm.

3. The white light photoluminescence wavelength conversion component of claim 1 , wherein the at least one yttrium aluminum garnet type phosphor, when excited, emits yellow light having a peak wavelength in a range 545 nm to 570 nm.

4. The white light photoluminescence wavelength conversion component of any claim 1 , wherein the orange to red organic fluorescent dye, when excited, emits orange light having a peak wavelength in a range 585 nm to 610 nm.

5. The white light photoluminescence wavelength conversion component of claim 1 , wherein the orange to red organic fluorescent dye, when excited, emits red light having a peak wavelength in a range 615 nm to 670 nm.

6. The white light photoluminescence wavelength conversion component of claim 1 , wherein the green to yellow yttrium aluminum garnet type phosphor and the orange to red light emitting organic fluorescent dye are incorporated in, and distributed throughout, a light transmissive substrate.

7. The white light photoluminescence wavelength conversion component of claim 1 , wherein the green to yellow yttrium aluminum garnet type phosphor and orange to red light emitting organic fluorescent dye comprise at least one layer on a light transmissive substrate.

8. The white light photoluminescence wavelength conversion component of claim 7 , wherein the green to yellow yttrium aluminum garnet type phosphor and red to orange light emitting organic fluorescent dye are incorporated in a light transmissive binder and comprise a respective separate layers.

9. The white light photoluminescence wavelength conversion component of claim 1 , wherein the green to yellow yttrium aluminum garnet type phosphor material and orange to red light emitting organic fluorescent dye comprise at least one layer on a light reflective substrate.

10. The white light photoluminescence wavelength conversion component of claim 9 , wherein the green to yellow yttrium aluminum garnet type phosphor and red to orange light emitting organic fluorescent dye are incorporated in a light transmissive binder and comprise a respective separate layers.

11. The white light photoluminescence wavelength conversion component of claim 1 , and further comprising particles of a light scattering material.

12. The white light photoluminescence wavelength conversion component of claim 11 , wherein the light scattering material is selected from the group consisting of:

magnesium oxide, titanium dioxide, barium sulfate and combinations thereof.

13. The white light photoluminescence wavelength conversion component of claim 11 , wherein the light scattering material has a particle size in a range selected from the group consisting of: 0.01 μm to 10 μm; 0.01 μm to 1 μm and 0.1 μm to 1 μm.

14. The white light photoluminescence wavelength conversion component of claim 11 , wherein the light scattering material comprises particles of a size such that the particles scatter blue light relatively more than light generated by the at least one green to yellow yttrium aluminum garnet type phosphor.

15. The white light photoluminescence wavelength conversion component of claim 14 , wherein the light scattering material has a particle size in a range 100 nm to 150 nm.

16. The white light photoluminescence wavelength conversion component of claim 1 , wherein the component, when excited by blue light, generates white light having a color rendering index of at least 80.

17. A white light emitting device comprising: a solid-state light emitter operable to generate blue light having a peak wavelength in a range 430 nm to 490 nm and a white light photoluminescence wavelength conversion component according to claim 1 .

18. The white light photoluminescence wavelength conversion component of claim 1 , wherein the at least one yttrium aluminum garnet type phosphor has a general composition (Y, M) 3 (Al, M′) 5 (O, M″) 12 :Ce 3+ in which

M is at least one of Tb, Gd, Sm, Lu, La, Sr, Ba, Ca and Mg;

M′ is at least one of Si, Ge, B, P and Ga; and

M″ is at least one of F, Cl, N and S and wherein there is partial substitution of one or more of the Y, Al or O by elements M, M′ and M″ respectively.

19. The white light photoluminescence wavelength conversion component of claim 1 , wherein the orange to red organic fluorescent dye comprises a perylene based dye or a rhodamine based dye.

20. The white light photoluminescence wavelength conversion component of claim 1 , wherein the organic fluorescent dye comprises approximately 0.005% by weight of the total photoluminescence material.

21. The white light photoluminescence wavelength conversion component of claim 1 , wherein the organic fluorescent dye comprises approximately 0.00002% by weight of the total photoluminescence material.

22. A white light photoluminescence wavelength conversion component comprising:

a polycarbonate light transmissive substrate;

at least one blue light excitable green to yellow yttrium aluminum garnet type phosphor, which when excited, emits green to yellow light having a peak wavelength in a range 510 nm to 570 nm; and

at least one blue light excitable orange to red light emitting organic fluorescent dye, which when excited, emits orange to red light having a peak wavelength in a range 585 nm to 670 nm;

wherein the green to yellow yttrium aluminum garnet type phosphor and the orange to red light emitting organic fluorescent dye are incorporated in, and distributed throughout, the light transmissive polycarbonate substrate; and

wherein organic fluorescent dye comprises less than 0.01% by weight of total photoluminescence material formed from a mixture of the organic fluorescent dye and one or more phosphor materials.