Quantum Dot Films, Lighting Devices, and Lighting Methods

• US 20160349428A1
• Filed: 02/08/2016
• Published: 12/01/2016
• Est. Priority Date: 12/30/2008
• Status: Active Grant

• Current Assignee: Shoei Chemical Inc.
• Original Assignee: Nanosys Incorporated (Shoei Electronic Materials, Inc.)
• Inventors: FURUTA, Paul, DUBROW, Robert S., FREEMAN, William P., LEE, Ernest
• Granted Patent: US 9,804,319 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B32B 2313/00 Elements other than metals
• CPC Class Codes: B32B 2457/202 LCD, i.e. liquid crystal displays
• CPC Class Codes: B32B 2551/00 Optical elements
• CPC Class Codes: B32B 5/16 characterised by features of a layer formed of particles, e.g. chips, powder or granules layer formed of natural mineral particles B32B19/00; layer being formed of wood fibres, chips or particles B32B21/02
• CPC Class Codes: B32B 9/04 comprising such particular substance as the main or only constituent of a layer, which is next to another layer of the same or of a different material next to a glass layer B32B17/06; layered products with at least two ceramic layers composed mainly of ceramic B32B18/00
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: F21V 9/30 Elements containing photoluminescent material distinct from or spaced from the light source shades F21V1/17; globes, bowls or cover glasses F21V3/08, F21V3/12; refractors F21V5/10; reflectors F21V7/26, F21V7/30; elements with provision for controlling the spectral properties or intensity F21V9/40
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: G02B 6/005 provided by one optical element, or plurality thereof, placed on the light output side of the light guide
• CPC Class Codes: G02B 6/0053 Prismatic sheet or layer; Brightness enhancement element, sheet or layer
• CPC Class Codes: G02B 6/0055 Reflecting element, sheet or layer
• CPC Class Codes: G02B 6/0061 to provide homogeneous light output intensity
• CPC Class Codes: G02B 6/0068 Arrangements of plural sources, e.g. multi-colour light sources
• CPC Class Codes: G02B 6/0073 Light emitting diode [LED]
• CPC Class Codes: G02F 1/133611 including means for improving the brightness uniformity
• CPC Class Codes: G02F 1/133614 using photoluminescence, e.g. phosphors illuminated by UV or blue light
• CPC Class Codes: Y10S 977/774 Exhibiting three-dimensional carrier confinement, e.g. quantum dots
• CPC Class Codes: Y10T 428/31504 Composite [nonstructural laminate]

Abstract

Light-emitting quantum dot films, quantum dot lighting devices, and quantum dot-based backlight units are provided. Related compositions, components, and methods are also described. Improved quantum dot encapsulation and matrix materials are provided. Quantum dot films with protective barriers are described. High-efficiency, high brightness, and high-color purity quantum dot-based lighting devices are also included, as well as methods for improving efficiency and optical characteristics in quantum dot-based lighting devices.

Claims

1. A display backlighting unit (BLU), comprising:

at least one primary light source that emits primary light;

a light guide panel (LGP) optically coupled to the at least one primary light source, whereby the primary light is transmitted uniformly through the LGP; and

a remote phosphor film, sandwiched between at least two barrier layers, comprising only two populations of light emitting quantum dots (QDs) including a first population of QDs configured to emit first secondary light and a second population of QDs configured to emit second secondary light at a different wavelength than the first secondary light;

wherein the remote phosphor film is not directly physically coupled to the LGP, wherein the primary light transmits uniformly through the LGP and into the remote phosphor film, whereby at least a portion of the primary light is absorbed by the two populations of QDs and reemitted by the QDs as the first and second secondary light, and

wherein the remote phosphor film comprises a plurality of spatial regions.

3. The display BLU of claim 1, wherein the spatial regions of the remote phosphor film are at a same planar layer of the BLU.

5. The display BLU of claim 3, wherein the same planar layer has a property that is uniform in the layer.

7. The display BLU of claim 3, wherein the same planar layer has a property that is varied in the layer.

9. The display BLU of claim 5, wherein the property is selected from the group consisting of:

thickness, shape, emission color, concentration of QDs, QD size, QD material composition, QD gradients, QD arrangements and combinations thereof.

10. The display BLU of claim 7, wherein the property is any selected from the group consisting of:

thickness, shape, emission color, concentration of QDs, QD size, QD material composition, QD gradients, QD arrangements and combinations thereof.

13. The display BLU of claim 1, wherein the remote phosphor film comprises a plurality of layers.

15. The display BLU of claim 1, wherein the remote phosphor film comprises a plurality of individual films cut from one or more larger phosphor films before being disposed in the spatial regions.

2. A display backlighting unit (BLU), comprising:

at least one primary light source that emits primary light; and

a plurality of remote phosphor films each disposed in separate spatial regions of the BLU, each remote phosphor film sandwiched between at least two barrier layers and comprising a quantum dot (QD) phosphor material comprising at least one population of QDs embedded in at least one matrix material, wherein the at least one population of QDs emit secondary light upon absorbance of the primary light;

wherein the remote phosphor films are not directly physically coupled to the light source, wherein the primary light transmits into the remote phosphor films, whereby at least a portion of the primary light is absorbed by the at least one population of QDs in the remote phosphor films and reemitted by the QDs as the secondary light having a longer wavelength than the primary light.

4. The display BLU of claim 2, wherein the separate spatial regions of the remote phosphor film are at a same planar layer of the BLU.

6. The display BLU of claim 4, wherein the same planar layer has a property that is uniform in the layer.

8. The display BLU of claim 4, wherein the same planar layer has a property that is varied in the layer.

11. The display BLU of claim 6, wherein the property is selected from the group consisting of:

thickness, shape, emission color, concentration of QDs, QD size, QD material composition, QD gradients, QD arrangements and combinations thereof.

12. The display BLU of claim 8, wherein the property is selected from the group consisting of:

thickness, shape, emission color, concentration of QDs, QD size, QD material composition, QD gradients, QD arrangements and combinations thereof.

14. The display BLU of claim 2, wherein each remote phosphor film comprises a plurality of layers.

16. The display BLU of claim 2, wherein the remote phosphor film comprises a plurality of individual films cut from one or more larger phosphor films before being disposed in the spatial regions.

17. A display backlighting unit (BLU), comprising:

at least one primary light source that emits primary light;

a light guide panel (LGP) optically coupled to the at least one primary light source, whereby the primary light is transmitted uniformly through the LGP; and

a remote phosphor film, sandwiched between at least two barrier layers, comprising at least two populations of light emitting quantum dots (QDs) including a first population of QDs configured to emit first secondary light and a second population of QDs configured to emit second secondary light at a different wavelength than the first secondary light;

wherein the remote phosphor film is not directly physically coupled to the LGP, wherein the primary light transmits uniformly through the LGP and into the remote phosphor film, whereby at least a portion of the primary light is absorbed by the at least two populations of QDs and reemitted by the QDs as the first and second secondary light, and wherein the remote phosphor film comprises a plurality of spatial regions.

19. The display BLU of claim 17, wherein the spatial regions of the remote phosphor film are at a same planar layer of the BLU.

21. The display BLU of claim 19, wherein the same planar layer has a property that is uniform in the layer.

23. The display BLU of claim 19, wherein the same planar layer has a property that is varied in the layer.

25. The display BLU of claim 21, wherein the property is selected from the group consisting of:

thickness, shape, emission color, concentration of QDs, QD size, QD material composition, QD gradients, QD arrangements and combinations thereof.

27. The display BLU of claim 23, wherein the property is selected from the group consisting of:

thickness, shape, emission color, concentration of QDs, QD size, QD material composition, QD gradients, QD arrangements and combinations thereof.

29. The display BLU of claim 17, wherein the remote phosphor film comprises a plurality of individual films cut from one or more larger phosphor films before being disposed in the spatial regions.

18. A display backlighting unit (BLU), comprising:

at least one primary light source that emits primary light;

a light guide panel (LGP) optically coupled to the at least one primary light source, whereby the primary light is transmitted uniformly through the LGP; and

a remote phosphor film, sandwiched between at least two barrier layers, comprising at least one population of light emitting quantum dots (QDs) configured to emit first secondary light;

wherein the remote phosphor film is not directly physically coupled to the LGP, wherein the primary light transmits uniformly through the LGP and into the remote phosphor film, whereby at least a portion of the primary light is absorbed by the at least one population of QDs and reemitted by the QDs as the first secondary light having a longer wavelength than the primary light, and

wherein the remote phosphor film comprises a plurality of spatial regions.

20. The display BLU of claim 18, wherein the spatial regions of the remote phosphor film are at a same planar layer of the BLU.

22. The display BLU of claim 20, wherein the same planar layer has a property that is uniform in the layer.

24. The display BLU of claim 20, wherein the same planar layer has a property that is varied in the layer.

26. The display BLU of claim 22, wherein the property is selected from the group consisting of:

thickness, shape, emission color, concentration of QDs, QD size, QD material composition, QD gradients, QD arrangements, and combinations thereof.

28. The display BLU of claim 24, wherein the property is selected from the group consisting of:

thickness, shape, emission color, concentration of QDs, QD size, QD material composition, QD gradients, QD arrangements and combinations thereof.

30. The display BLU of claim 18, wherein the remote phosphor film comprises a plurality of individual films cut from one or more larger phosphor films before being disposed in the spatial regions.