Luminescent device

• US 8,847,487 B2
• Filed: 07/10/2013
• Issued: 09/30/2014
• Est. Priority Date: 11/13/2006
• Status: Active Grant

• Current Assignee: Research Triangle Institute
• Original Assignee: Research Triangle Institute
• Inventors: Davis, James Lynn, Andrady, Anthony L., Ensor, David S., Han, Li, Walls, Howard J.
• Primary Examiner(s): Hanley, Britt D
• Application Number:
  US13/938,754
• Publication Number:
  US 20130308334A1
• Time in Patent Office: 447 Days
• Field of Search: None
• US Class Current: 313/512
• CPC Class Codes: C09K 11/565 with zinc cadmium
• CPC Class Codes: C09K 11/883 with zinc or cadmium
• CPC Class Codes: D01D 5/0007 Electro-spinning non-woven fabrics produced by electro-spinning D04H1/728
• CPC Class Codes: D01F 11/00 Chemical after-treatment of artificial filaments or the like during manufacture
• CPC Class Codes: D04H 1/413 containing granules other than absorbent substances
• CPC Class Codes: D04H 1/42 characterised by the use of certain kinds of fibres insofar as this use has no preponderant influence on the consolidation of the fleece
• CPC Class Codes: D04H 1/43838 Ultrafine fibres, e.g. microfibres
• CPC Class Codes: D06M 11/52 with selenium, tellurium, polonium or their compounds; with sulfur, dithionites or compounds containing sulfur and halogens, with or without oxygen; by sulfohalogenation with chlorosulfonic acid; by sulfohalogenation with a mixture of sulfur dioxide and free halogens
• CPC Class Codes: G02B 6/0008 the light being emitted at the end of the fibre
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01L 33/501 characterised by the materials, e.g. binder

Abstract

A device for stimulable light emission that includes a fiber mat of nanofibers having an average fiber diameter in a range between 100 and 2000 nm, and includes plural stimulable particles disposed in association with the nanofibers. The stimulable particles produce secondary light emission upon receiving primary light at a wavelength λ. The average fiber diameter is comparable in size to the wavelength λ in order to provide scattering sites within the fiber mat for the primary light. Various methods for making suitable luminescent nanofiber mats include: electrospinning a polymer solution including or not including the stimulable particles and forming from the electrospun solution nanofibers having an average fiber diameter between 100 and 2000 nm. Methods, which electrospin without the stimulable particles, introduce the stimulable particles during electrospinning or after electrospinning to the fibers and therefore to the resultant fiber mat.

Claims

1. A light scattering device comprising:

a prefabricated fiber mat configured for disposition in a respective area in a vicinity of a lamp and comprising plural layers of fibers;

said fibers in the fiber mat having an average fiber diameter between 100 and 2000 nm and individually comprising scattering centers for visible light emitted from the lamp; and

said fibers layered on each other to form an optical path length in the fiber mat which scatters at least one ray of the visible light incident on the fiber mat multiple times before exiting the fiber mat,

further comprising an encapsulant disposed in contact with and at least partially encapsulating the fibers of the fiber mat.

2. The device of claim 1, wherein the encapsulant comprises an encapsulant filing interstices in the fibers.

3. The device of claim 1, wherein the encapsulant comprises a substantially transparent encapsulant.

4. The device of claim 1, further comprising stimulable particles disposed in the fiber mat and configured to emit photons upon absorption of the visible light.

5. The device of claim 1, further comprising additives to alter at least one of a refractive index, UV stability, and an electrical conductivity of the nanofibers in the fiber mat.

6. The device of claim 5, wherein the additive is a ceramic.

7. The device of claim 6, wherein the ceramic comprises at least one of zirconium oxide, zinc oxide, zinc sulfide, zinc selenide, zinc silicate, titanium sulfide, titanium oxide, and tin oxide.

8. The device of claim 1, wherein the fibers comprises organic fibers.

9. The device of claim 8, wherein the fibers comprises polymers including at least one of poly(alkyl acrylate), poly(methyl methacrylate), poly(ethylene oxide), polystyrene, polysulfone, polylactides, polycarbonate, polyamides, poly(vinyl alcohol), derivatives thereof, polysilicones, polysulfones, polypropylene, and combinations thereof.

10. The device of claim 1, wherein the fiber mat has a total thickness of less than 3,000 microns.

11. The device of claim 1, wherein the fibers comprises a first group of said fibers and a second group of differently-sized fibers.

14. The device of claim 1, wherein the fiber mat has a thickness in a range between 1 micron and 2,000 microns.

15. The device of claim 1, wherein the fiber mat has a thickness in a range between 50 to 300 microns.

16. The device of claim 1, wherein the fibers in the fiber mat comprise different materials.

17. The device of claim 1, wherein the fibers in the fiber mat comprise substantially transparent fibers.

12. A light scattering device comprising:

a prefabricated fiber mat configured for disposition in a respective area in a vicinity of a lamp and comprising plural layers of fibers;

said fibers in the fiber mat having an average fiber diameter between 100 and 2000 nm and individually comprising scattering centers for visible light emitted from the lamp; and

said fibers layered on each other to form an optical path length in the fiber mat which scatters at least one ray of the visible light incident on the fiber mat multiple times before exiting the fiber mat, wherein the fibers comprises a first group of said fibers and a second group of differently-sized fibers, and said first group and second group are disposed on respective sides of the fiber mat.

13. The device of claim 12, wherein said average fiber diameter of the first group is between 100 and 600 nm.

18. A fiber-based light scattering device comprising:

a fiber mat including, fibers having an average fiber diameter in a range between 100 and 2000 nm;

said fibers providing individual scattering centers within the fiber mat for scattering visible light incident on the fiber mat; and

said fibers layered on each other to form an optical path length in the fiber mat which scatters at least one ray of the visible light multiple times before exiting the fiber mat; and

an encapsulant disposed in contact with and at least partially encapsulating the fibers of the fiber mat.

19. The device of claim 18, wherein the average fiber diameter is in a range between 100 to 600 nm.

20. The device of claim 18, wherein the average fiber diameter is in a range between 200 nm to 500 nm.

21. The device of claim 18, wherein a wavelength λ

of the visible light is in a range between 300 and 600 nanometers.

22. The device of claim 18, wherein the fibers in the fiber mat comprise substantially transparent fibers.

23. The device of claim 18, wherein the fiber mat has a thickness in a range between 1 micron and 2,000 microns.

24. The device of claim 18, wherein the fiber mat has a thickness in a range between 50 to 300 microns.

25. The device of claim 18, wherein the nanofibers include additives to alter at least one of a refractive index, UV stability, and an electrical conductivity of the nanofibers in the fiber mat.

26. The device of claim 25, wherein the additive is a ceramic.

27. The device of claim 18, further comprising an encapsulant disposed in contact with and at least partially encapsulating the fibers of the fiber mat.

28. A fiber-based light scattering device comprising:

a fiber mat including, fibers having an average fiber diameter in a range between 100 and 2000 nm;

said fibers providing individual scattering centers within the fiber mat for scattering visible light incident on the fiber mat;

said fibers layered on each other to form an optical path length in the fiber mat which scatters at least one ray of the visible light multiple times before exiting the fiber mat; and

an encapsulant disposed in contact with and at least partially encapsulating the fibers of the fiber mat.