Photoluminescent daylight panel

1. A photoluminescent daylight panel for converting higher energy shorter wavelength daylight to lower energy longer wavelength light, the panel comprising:

a light transmissive substrate; and

at least one photoluminescent material configured to absorb at least a portion of daylight radiation of wavelengths between about 350 nm and about 450 nm and convert it to light with a wavelength greater than about 600 nm;

wherein the at least one photoluminescent material is incorporated within the light transmissive substrate.

2. The panel of claim 1 , wherein the at least one photoluminescent material comprises one or more phosphors.

3. The panel of claim 1 , wherein the at least one photoluminescent material comprises quantum dots.

4. The panel of claim 1 , wherein the at least one photoluminescent material comprises an orange silicate-based phosphor of general composition A 3 Si(O,D) 5 in which A is at least one of Sr, Ba, Mg and Ca and D is a at least one of Cl, F, N and S.

5. The panel of claim 4 , wherein the silicate-based orange phosphor has a formula (Sr 1-x M x ) y Eu z SiO 5 , in which M is at least one of a divalent metal Ba, Mg, Ca and Zn; 0≦x≦0.5; 2.6≦y≦3.3; 0.001≦z≦0.5 and y is not 3 when M is Ba.

6. The panel of claim 1 , wherein the at least one photoluminescent material comprises an aluminum-silicate-based orange phosphor of general composition (Sr 1-x-y M x T y ) 3-m Eu m (Si 1-z Al z )O 5 , in which M is at least one of a divalent metal Ba, Mg, and Ca; T is a trivalent metal Y, La, Ce, Pr, Nd, Pm, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Th, Pa and U; 0≦x≦0.4; 0≦y≦0.4; 0≦z≦0.2; and 0.001≦m≦0.5.

7. The panel of claim 6 , wherein the aluminum-silicate-based orange phosphor further comprises a halogen F, Cl or Br.

8. The panel of claim 7 , wherein the halogen resides on oxygen lattice sites within silicate crystal.

9. The panel of claim 1 , wherein the at least one photoluminescent material is a silicate-based yellow phosphor of general composition A 2 Si(O,D) 4 in which A comprises at least one Sr, Ca, Ba, Mg, Zn and Cd and D is a is at least one F, Cl, Br, I, P, S and N.

10. The panel of claim 9 , wherein the dopant D is present in the phosphor in an amount ranging from about 0.01 to 20 mole percent.

11. The panel of claim 10 , wherein at least some of the dopant substitutes for oxygen anions to become incorporated into the crystal lattice of the phosphor.

12. The panel of claim 9 , wherein the silicate-based yellow phosphor has the formula (Sr 1-x- Ba x M y ) 2 Si(O,D) 4 :Eu 2+ in which 0≦x≦1 and where 0≦y≦1 when M is Ca; 0≦y≦1 when M is Mg; and 0≦y≦1 when M is Zn and Cd.

13. The panel of claim 1 , wherein the at least one photoluminescent material is a phosphor selected from the group consisting of:

Sr 1.36 Ba 0.55 Mg 0.55 Eu 0.10 Si 1.03 O 4 Cl 0.18 ;

Sr 1.6 Ba 0.35 Mg 0.05 Eu 0.06 Si 1.03 O 4 Cl 0.12 ;

Sr 1.57 Ba 0.34 Mg 0.05 Eu 0.10 Si 1.03 O 4 Cl 0.18 ;

Sr. 64 Ba 0.27 Mg 0.05 Eu 0.10 Si 1.03 O 4 Cl 0.18 ;

Sr 3 Eu 0.06 Si 1.02 O 5 F 0.18 ;

Sr 2.94 Ba 0.06 Eu 0.06 Si 1.02 O 5 F 0.18 ;

(Sr 0.9 Ba 0.1 ) 2.76 Eu 0.06 Si 1.02 O 5 F 0.18 ;

(Sr 0.87 Ba 0.1 Y 0.03 ) 2.94 Eu 0.06 (Si 0.9 Al 0.1 )O 5 F 0.18 ;

and combinations thereof.

14. The panel of claim 1 , wherein the light transmissive substrate is planar.

15. A photoluminescent daylight panel for converting higher energy shorter wavelength daylight to lower energy longer wavelength light, the panel comprising:

a light transmissive substrate; and

at least one photoluminescent material configured to absorb at least a portion of daylight radiation of wavelengths between about 350 nm and about 450 nm and convert it to light with a wavelength greater than about 600 nm;

wherein the at least one photoluminescent material is distributed in a wavelength conversion layer on the light transmissive substrate; and

further comprising a light diffusing layer on a surface of the layer of at least one photoluminescent material.

16. The panel of claim 15 , and further comprising a further light transmissive substrate, the wavelength conversion layer being located between the light transmissive substrate and the further light transmissive substrate.

17. The panel of claim 15 , wherein the light transmissive substrate is planar.

18. The panel of claim 15 , wherein the at least one photoluminescent material comprises one or more phosphors or quantum dots.

19. The panel of claim 15 , wherein the at least one photoluminescent material comprises an orange silicate-based phosphor of general composition A 3 Si(O,D) 5 in which A is at least one of Sr, Ba, Mg and Ca and D is a at least one of Cl, F, N and S, or wherein the at least one photoluminescent material comprises an aluminum-silicate-based orange phosphor of general composition (Sr 1-x-y M x T y ) 3-m Eu m (Si 1-z Al z )O 5 , in which M is at least one of a divalent metal Ba, Mg, and Ca; T is a trivalent metal Y, La, Ce, Pr, Nd, Pm, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Th, Pa and U; 0≦x≦0.4; 0≦y≦0.4; 0≦z≦0.2; and 0.001<m<0.5.

20. The panel of claim 19 , wherein the silicate-based orange phosphor has a formula (Sr 1-x M x ) y Eu z SiO 5 , in which M is at least one of a divalent metal Ba, Mg, Ca and Zn; 0<x≦0.5; 2.6≦y≦3.3; 0.001≦z≦0.5 and y is not 3 when M is Ba, or wherein the aluminum-silicate-based orange phosphor further comprises a halogen F, Cl or Br.

21. The panel of claim 20 , wherein the halogen resides on oxygen lattice sites within silicate crystal.

22. The panel of claim 15 , wherein the at least one photoluminescent material is a silicate-based yellow phosphor of general composition A 2 Si(O,D) 4 in which A comprises at least one Sr, Ca, Ba, Mg, Zn and Cd and D is a is at least one F, Cl, Br, I, P, S and N.

23. The panel of claim 22 , wherein the dopant D is present in the phosphor in an amount ranging from about 0.01 to 20 mole percent.

24. The panel of claim 23 , wherein at least some of the dopant substitutes for oxygen anions to become incorporated into the crystal lattice of the phosphor.

25. The panel of claim 22 , wherein the silicate-based yellow phosphor has the formula (Sr 1-x- Ba x M y ) 2 Si(O,D) 4 :Eu 2+ in which 0≦x≦1 and where 0≦y≦1 when M is Ca; 0≦y≦1 when M is Mg; and 0≦y≦1 when M is Zn and Cd.

26. The panel of claim 15 , wherein the at least one photoluminescent material is a phosphor selected from the group consisting of:

Sr 1.36 Ba 0.55 Mg 0.05 Eu 0.10 Si 1.03 O 4 Cl 0.18 ;

Sr 1.6 Ba 0.35 Mg 0.05 Eu 0.06 Si 1.03 O 4 Cl 0.12 ;

Sr 1.57 Ba 0.34 Mg 0.05 Eu 0.10 Si 1.03 O 4 Cl 0.18 ;

Sr 0.64 Ba 0.27 Mg 0.05 Eu 0.10 Si 1.03 O 4 Cl 0.18 ;

Sr 3 Eu 0.06 Si 1.02 O 5 F 0.18 ;

Sr 2.94 Ba 0.06 Eu 0.06 Si 1.02 O 5 F 0.18 ;

(Sr 0.9 Ba 0.1 ) 2.76 Eu 0.06 Si 1.02 O 5 F 0.18 ;

(Sr 0.87 Ba 0.1 Y 0.03 ) 2.94 Eu 0.06 (Si 0.9 Al 0.1 )O 5 F 0.18 ;

and combinations thereof.

27. A light tube for providing daylight to an interior of a structure, comprising:

a first light transmissive surface exposed to the daylight;

a second light transmissive surface exposed to the interior of the structure; and

a light reflective tubular chamber for guiding light between the first surface and the second surface; and

at least one photoluminescent material for converting higher energy shorter wavelength daylight to lower energy longer wavelength light, the at least one photoluminescent material configured to absorb at least a portion of daylight radiation of wavelengths between about 350 nm and about 450 nm and convert it to light with a wavelength greater than about 600 nm.

28. The light tube of claim 27 , wherein the first surface includes the at least one photoluminescent material.

29. The light tube of claim 27 , wherein the second surface includes the photoluminescent material.

30. The light tube of claim 27 , wherein the photoluminescent material is distributed in a light transmissive substrate located between the first and second surfaces.

31. The light tube of claim 27 , wherein the photoluminescent material is distributed in a wavelength conversion layer, the wavelength conversion layer and a light transmissive substrate forming a panel that is situated between the first and second surfaces.

32. The light tube of claim 31 , wherein the panel covers at least a part of an inner surface of the light tube.

33. The light tube of claim 27 , wherein the at least one photoluminescent material comprises an orange silicate-based phosphor of general composition A 3 Si(O,D) 5 in which A is at least one of Sr, Ba, Mg and Ca and D is a at least one of Cl, F, N and S.

34. The light tube of claim 33 , wherein the silicate-based orange phosphor has a formula (Sr 1-x M x ) y Eu z SiO 5 , in which M is at least one of a divalent metal Ba, Mg, Ca and Zn; 0<x≦0.5; 2.6≦y≦3.3; 0.001≦z≦0.5 and y is not 3 when M is Ba.

35. The light tube of claim 27 , wherein the at least one photoluminescent material comprises an aluminum-silicate-based orange phosphor of general composition (Sr 1-x-y M x T y ) 3-m Eu m (Si 1-z Al z )O 5 , in which M is at least one of a divalent metal Ba, Mg, and Ca; T is a trivalent metal Y, La, Ce, Pr, Nd, Pm, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Th, Pa and U; 0≦x≦0.4; 0≦y≦0.4; 0≦z≦0.2; and 0.001≦m≦0.5.

36. The light tube of claim 35 , wherein the aluminum-silicate-based orange phosphor further comprises a halogen F, Cl or Br.

37. The light tube of claim 36 , wherein the halogen resides on oxygen lattice sites within the silicate crystal.

38. The light tube of claim 27 , wherein the at least one photoluminescent material is a silicate-based yellow phosphor of general composition A 2 Si(O,D) 4 in which A comprises at least one Sr, Ca, Ba, Mg, Zn and Cd and D is a is at least one F, Cl, Br, I, P, S and N.

39. The light tube of claim 38 , wherein the dopant D is present in the phosphor in an amount ranging from about 0.01 to 20 mole percent.

40. The light tube of claim 39 , wherein at least some of the dopant substitutes for oxygen anions to become incorporated into the crystal lattice of the phosphor.

41. The light tube of claim 31 , wherein the silicate-based yellow phosphor has the formula (Sr 1-x- Ba x M y ) 2 Si(O,D) 4 :Eu 2+ in which 0≦x≦1 and where 0≦y≦1 when M is Ca; 0≦y≦1 when M is Mg; and 0≦y≦1 when M is Zn and Cd.

42. The light tube of claim 27 , wherein the at least one photoluminescent material is a phosphor selected from the group consisting of:

Sr 1.36 Ba 0.55 Mg 0.55 Eu 0.10 Si 1.03 O 4 Cl 0.18 ;

Sr 1.6 Ba 0.35 Mg 0.05 Eu 0.06 Si 1.03 O 4 Cl 0.12 ;

Sr 1.57 Ba 0.34 Mg 0.05 Eu 0.10 Si 1.03 O 4 Cl 0.18 ;

Sr 0.64 Ba 0.27 Mg 0.05 Eu 0.10 Si 1.03 O 4 Cl 0.18 ;

Sr 3 Eu 0.06 Si 1.02 O 5 F 0.18 ;

Sr 2.94 Ba 0.06 Eu 0.06 Si 1.02 O 5 F 0.18 ;

(Sr 0.9 Ba 0.1 ) 2.76 Eu 0.06 Si 1.02 O 5 F 0.18 ;

(Sr 0.87 Ba 0.1 Y 0.03 ) 2.94 Eu 0.06 (Si 0.9 Al 0.1 )O 5 F 0.18 ;

and combinations thereof.