Low rare earth mineral photoluminescent compositions and structures for generating long-persistent luminescence

• US 8,952,341 B2
• Filed: 09/06/2012
• Issued: 02/10/2015
• Est. Priority Date: 09/06/2012
• Status: Active Grant

• Current Assignee: Performance Indicator, LLC
• Original Assignee: Performance Indicator, LLC
• Inventors: Kingsley, Edward D., Agrawal, Satish
• Primary Examiner(s): Porta, David
• Assistant Examiner(s): VU, MINDY D
• Application Number:
  US13/604,699
• Publication Number:
  US 20140061504A1
• Time in Patent Office: 887 Days
• Field of Search: 250/486.1, 250/458.1, 250/459.1, 252/301.36, 252/301.5, 252/301.4 R, 252/301.4 S, 252/301.4 P, 252/301.4 F, 252/301.4 H, 252/301.6 R, 252/301.6 S, 252/301.6 F, 252/301.6 P
• US Class Current: 250/486.1
• CPC Class Codes: B32B 2307/422 Luminescent, fluorescent, phosphorescent
• CPC Class Codes: C09K 11/7792 Aluminates

Abstract

A low rare earth mineral photoluminescent structure for generating long-persistent luminescence that utilizes at least a phosphorescent layer comprising one or more phosphorescent materials having substantially low rare earth mineral content of less than about 2.0 weight percent, and one or more fluorescent layers is disclosed. Further disclosed are methods for fabricating and using the inventive low rare earth mineral photoluminescent structure. A low rare earth mineral photoluminescent composition for generating long-persistent luminescence that utilizes at least one or more phosphorescent materials having substantially low rare earth mineral content of less than about 2.0 weight percent and one or more fluorescent materials is also disclosed, as well as, the methods for fabricating and using the inventive low rare earth mineral photoluminescent composition.

Claims

1. A low rare earth mineral photoluminescent structure for generating long-persistent luminescence, said low rare earth mineral photoluminescent structure comprising:

a phosphorescent layer that substantially converts at least a portion of incident electromagnetic radiation to a primary emission, said phosphorescent layer comprising one or more phosphorescent materials having substantially low rare earth mineral content of less than about 2.0 weight percent with an absorption spectrum that at least partially overlaps with incident electromagnetic radiation, and

one or more fluorescent layers that wholly or partially convert at least said primary emission to a secondary emission, said one or more fluorescent layers having an absorption spectrum that overlaps with at least a portion of said primary emission, and

wherein said primary emission and said secondary emission being of long-persistent luminescence.

2. The low rare earth mineral photoluminescent structure of claim 1, wherein said phosphorescent layer further comprises one or more other phosphorescent materials having an absorption spectrum that at least partially overlaps with at least one of incident electromagnetic radiation, the emission spectrum of said one or more phosphorescent materials, or the secondary emission.

3. The low rare earth mineral photoluminescent structure of claim 2, wherein said one or more other phosphorescent materials having an emission spectrum that at least partially overlaps with the absorption spectrum of said one or more phosphorescent materials.

4. The low rare earth mineral photoluminescent structure of claim 1, wherein said phosphorescent layer being disposed over said one or more fluorescent layers, such that a surface of said phosphorescent layer is exposed to incident electromagnetic radiation.

5. The low rare earth mineral photoluminescent structure of claim 4, wherein another said one or more fluorescent layers being overlaid onto said phosphorescent layer, such that a surface of one of said another said one or more fluorescent layers is exposed to incident electromagnetic radiation.

6. The low rare earth mineral photoluminescent structure of claim 4, wherein said phosphorescent layer additionally provides at least one of mechanical, chemical, or photolytic stability to said one or more fluorescent layers.

7. The low rare earth mineral photoluminescent structure of claim 1, wherein said one or more fluorescent layers being disposed over said phosphorescent layer, such that a surface of one of said one or more fluorescent layers is exposed to incident electromagnetic radiation.

8. The low rare earth mineral photoluminescent structure of claim 1, further comprising a substrate that provides base support for said low rare earth mineral photoluminescent structure.

9. The low rare earth mineral photoluminescent structure of claim 1, further comprising a UV layer that substantially enhances stability of said one or more fluorescent layers through absorption of at least a portion of incident ultraviolet electromagnetic radiation.

10. The low rare earth mineral photoluminescent structure of claim 1, wherein said phosphorescent layer further comprises one or more UV absorbers that substantially enhance stability of said one or more fluorescent layers through absorption of at least a portion of incident ultraviolet electromagnetic radiation.

11. The low rare earth mineral photoluminescent structure of claim 1, further comprising a reflection layer that redirects at least a portion of radiation emitted in at least one of said phosphorescent layer or said one or more fluorescent layers.

12. The low rare earth mineral photoluminescent structure of claim 11, wherein said reflection layer additionally functions as a substrate that provides base support for said low rare earth mineral photoluminescent structure.

13. The low rare earth mineral photoluminescent structure of claim 1, further comprising a protective layer that provides at least one of mechanical, chemical, or photolytic durability to said low rare earth mineral photoluminescent structure.

14. A method for fabricating a low rare earth mineral photoluminescent structure for generating long-persistent luminescence, said method comprising:

forming a phosphorescent layer that substantially converts at least a portion of incident electromagnetic radiation to a primary emission, said phosphorescent layer comprising one or more phosphorescent materials having substantially low rare earth mineral content of less than about 2.0 weight percent with an absorption spectrum that at least partially overlaps with incident electromagnetic radiation, and

forming one or more fluorescent layers that wholly or partially convert at least said primary emission to a secondary emission, said one or more fluorescent layers having an absorption spectrum that overlaps with at least a portion of said primary emission, and

wherein said primary emission and said secondary emission being of long-persistent luminescence.

15. The method of claim 14, wherein said phosphorescent layer further comprises one or more other phosphorescent materials having an absorption spectrum that at least partially overlaps with at least one of incident electromagnetic radiation, the emission spectrum of said one or more phosphorescent materials, or the secondary emission.

16. The method of claim 15, wherein said one or more other phosphorescent materials having an emission spectrum that at least partially overlaps with the absorption spectrum of said one or more phosphorescent materials.

17. The method of claim 14, further comprising disposing said phosphorescent layer over said one or more fluorescent layers, such that a surface of said phosphorescent layer is exposed to incident electromagnetic radiation.

18. The method of claim 17, further comprising overlaying another said one or more fluorescent layers onto said phosphorescent layer, such that a surface of one of said another said one or more fluorescent layers is exposed to incident electromagnetic radiation.

19. The method of claim 14, further comprising disposing said one or more fluorescent layers onto said phosphorescent layer, such that a surface of one of said one or more fluorescent layers is exposed to incident electromagnetic radiation.

20. The method of claim 14, further comprising rendering said phosphorescent layer or one of said one or more fluorescent layers onto or into a substrate that provides base support for said low rare earth mineral photoluminescent structure.

21. The method of claim 14, further comprising incorporating one or more UV absorbers into said phosphorescent layer, wherein said one or more UV absorbers substantially enhance stability of said one or more fluorescent layers through absorption of at least a portion of incident ultraviolet electromagnetic radiation.

22. The method of claim 14, further comprising overlaying a UV layer onto a surface of one of said phosphorescent layer or one of said one or more fluorescent layers, wherein said UV layer substantially enhances stability of said one or more fluorescent layers.

23. The method of claim 14, further comprising applying a reflection layer disposed over a surface of one of said phosphorescent layer or one of said one or more fluorescent layers, the surface not having another layer disposed on the surface, wherein said reflection layer redirects at least a portion of radiation emitted in at least one of said phosphorescent layer or said one or more fluorescent layers.

24. The method of claim 14, further comprising rendering a protective layer over a surface of one of said phosphorescent layer or one of said one or more fluorescent layers, the surface not having another layer disposed on the surface, wherein said protective layer provides at least one of mechanical, chemical, or photolytic durability to said low rare earth mineral photoluminescent structure.

25. A method for generating long-persistent luminescence, said method comprising:

providing a low rare earth mineral photoluminescent structure, said low rare earth mineral photoluminescent structure comprising;

(i) a phosphorescent layer comprising one or more phosphorescent materials having substantially low rare earth mineral content of less than about 2.0 weight percent with an absorption spectrum that at least partially overlaps with incident electromagnetic radiation, and

(ii) one or more fluorescent layers having an absorption spectrum that overlaps with at least a portion of a primary emission, and

wherein said low rare earth mineral photoluminescent structure is subsequently exposed to incident electromagnetic radiation and said phosphorescent layer substantially converts at least a portion of incident electromagnetic radiation to said primary emission, and said one or more fluorescent layers wholly or partially convert at least said primary emission to a secondary emission, and

wherein said primary emission and said secondary emission being of long-persistent luminescence.

26. The method of claim 25, wherein said phosphorescent layer further comprises one or more other phosphorescent materials having an absorption spectrum that at least partially overlaps with at least one of incident electromagnetic radiation, the emission spectrum of said one or more phosphorescent materials, or the secondary emission.

27. The method of claim 26, wherein said one or more other phosphorescent materials having an emission spectrum that at least partially overlaps with the absorption spectrum of said one or more phosphorescent materials.

28. The method of claim 25, wherein said low rare earth mineral photoluminescent structure further comprises a substrate that provides base support for said low rare earth mineral photoluminescent structure.

29. The method of claim 25, wherein said phosphorescent layer further comprises one or more UV absorbers that substantially enhance stability of said one or more fluorescent layers through absorption of at least a portion of incident ultraviolet electromagnetic radiation.

30. The method of claim 25, wherein said low rare earth mineral photoluminescent structure further comprises a UV layer that substantially enhances stability of said one or more fluorescent layers through absorption of at least a portion of incident ultraviolet electromagnetic radiation.

31. The method of claim 25, wherein said low rare earth mineral photoluminescent structure further comprises a reflection layer that redirects at least a portion of radiation emitted in at least one of said phosphorescent layer or said one or more fluorescent layers.

32. The method of claim 25, wherein said low rare earth mineral photoluminescent structure further comprises a protective layer that provides at least one of mechanical, chemical, or photolytic durability to said low rare earth mineral photoluminescent structure.

33. A low rare earth mineral photoluminescent composition for generating long-persistent luminescence, said low rare earth mineral photoluminescent composition comprising:

one or more phosphorescent materials that substantially convert at least a portion of incident electromagnetic radiation to a primary emission, said one or more phosphorescent materials having substantially low rare earth mineral content of less than about 2.0 weight percent with an absorption spectrum that at least partially overlaps with incident electromagnetic radiation, and

one or more fluorescent materials that wholly or partially convert at least said primary emission to a secondary emission, said one or more fluorescent materials having an absorption spectrum that overlaps with at least a portion of said primary emission, and

wherein said one or more phosphorescent materials substantially enhance stability of said one or more fluorescent materials, and

wherein said primary emission and said secondary emission being of long-persistent luminescence.

34. The low rare earth mineral photoluminescent composition of claim 33, further comprising one or more other phosphorescent materials having an absorption spectrum that at least partially overlaps with at least one of incident electromagnetic radiation, the emission spectrum of said one or more phosphorescent materials, or the secondary emission.

35. The low rare earth mineral photoluminescent composition of claim 34, wherein said one or more other phosphorescent materials having an emission spectrum that at least partially overlaps with the absorption spectrum of said one or more phosphorescent materials.

36. The low rare earth mineral photoluminescent composition of claim 33, wherein said low rare earth mineral photoluminescent composition being disposed into or onto a substrate that provides base support for said low rare earth mineral photoluminescent composition.

37. The low rare earth mineral photoluminescent composition of claim 33, wherein said low rare earth mineral photoluminescent composition being disposed onto a reflection layer that redirects at least a portion of radiation emitted in said low rare earth mineral photoluminescent composition.

38. The low rare earth mineral photoluminescent composition of claim 37, wherein said reflection layer additionally functions as a substrate that provides base support for said low rare earth mineral photoluminescent composition.

39. The low rare earth mineral photoluminescent composition of claim 33, further comprising one or more UV absorbers that further substantially enhance stability of said one or more fluorescent materials through absorption of at least a portion of incident ultraviolet electromagnetic radiation.

40. The low rare earth mineral photoluminescent composition of claim 33, wherein said low rare earth mineral photoluminescent composition being disposed onto a surface of one or more fluorescent layers, such that a longer emissive wavelength is produced.

41. A method for fabricating a composition for generating long-persistent luminescence, said method comprising:

incorporating one or more phosphorescent materials having substantially low rare earth mineral content of less than about 2.0 weight percent with an absorption spectrum that at least partially overlaps with incident electromagnetic radiation, and one or more fluorescent materials having an absorption spectrum that overlaps with at least a portion of a primary emission into the composition, the composition being a low rare earth mineral photoluminescent composition,

wherein said low rare earth mineral photoluminescent composition, when subsequently exposed to incident electromagnetic radiation, said one or more phosphorescent materials substantially convert at least a portion of incident electromagnetic radiation to said primary emission, and said one or more fluorescent materials wholly or partially convert at least said primary emission to a secondary emission, and

wherein said one or more phosphorescent materials substantially enhance stability of said one or more fluorescent materials, and

wherein said primary emission and said secondary emission being of long-persistent luminescence.

42. The method of claim 41, further comprising incorporating one or more other phosphorescent materials into the low rare earth mineral photoluminescent composition, wherein said one or more other phosphorescent materials having an absorption spectrum that at least partially overlaps with at least one of incident electromagnetic radiation, the emission spectrum of said one or more phosphorescent materials, or the secondary emission.

43. The method of claim 42, wherein said one or more other phosphorescent materials having an emission spectrum that at least partially overlaps with the absorption spectrum of said one or more phosphorescent materials.

44. The method of claim 41, further comprising depositing one or more UV absorbers into said low rare earth mineral photoluminescent composition, wherein said one or more UV absorbers further substantially enhance stability of said one or more fluorescent materials through absorption of at least a portion of incident ultraviolet electromagnetic radiation.

45. A method for generating long-persistent luminescence, said method comprising:

providing a low rare earth mineral photoluminescent composition, said low rare earth mineral photoluminescent composition comprising;

(i) one or more phosphorescent materials having substantially low rare earth mineral content of less than about 2.0 weight percent with an absorption spectrum that at least partially overlaps with incident electromagnetic radiation, and

(ii) one or more fluorescent materials having an absorption spectrum that overlaps with at least a portion of a primary emission, and

wherein said low rare earth mineral photoluminescent composition is subsequently exposed to incident electromagnetic radiation, and said one or more phosphorescent materials substantially convert at least a portion of incident electromagnetic radiation to said primary emission, and said one or more fluorescent materials wholly or partially convert at least said primary emission to a secondary emission, and

wherein said one or more phosphorescent materials substantially enhance stability of said one or more fluorescent materials, and

wherein said primary emission and said secondary emission being of long-persistent luminescence.

46. The method of claim 45, wherein said low rare earth mineral photoluminescent composition further comprises one or more other phosphorescent materials having an absorption spectrum that at least partially overlaps with at least one of incident electromagnetic radiation, the emission spectrum of said one or more phosphorescent materials, or the secondary emission.

47. The method of claim 46, wherein said one or more other phosphorescent materials having an emission spectrum that at least partially overlaps with the absorption spectrum of said one or more phosphorescent materials.

48. The method of claim 45, wherein said low rare earth mineral photoluminescent composition further comprises one or more UV absorbers that further substantially enhance stability of said one or more fluorescent materials through absorption of at least a portion of incident ultraviolet electromagnetic radiation.

49. The method of claim 45, further comprising depositing said low rare earth mineral photoluminescent composition onto or into a substrate that provides support for said low rare earth mineral photoluminescent composition.

50. The method of claim 45, further comprising depositing said low rare earth mineral photoluminescent composition onto a reflection layer that redirects at least a portion of radiation emitted in said low rare earth mineral photoluminescent composition.

51. The method of claim 45, further comprising depositing said low rare earth mineral photoluminescent composition onto a surface of one or more fluorescent layers, such that a longer emissive wavelength is produced.