Quantum Dot Films, Lighting Devices, and Lighting Methods

• US 20160363713A1
• Filed: 08/23/2016
• Published: 12/15/2016
• Est. Priority Date: 12/30/2008
• Status: Active Grant

• Current Assignee: Shoei Chemical Inc.
• Original Assignee: Nanosys Incorporated (Shoei Electronic Materials, Inc.)
• Inventors: Dubrow, Robert S., Freeman, William P., Lee, Ernest, Furuta, Paul
• Granted Patent: US 10,302,845 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:

(a) at least one primary light source that emits primary light;

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

(c) a remote phosphor film comprising at least two populations of light emitting quantum dots (QDs), wherein the remote phosphor film is disposed over the LGP, wherein the primary light transmits through the LGP and into the remote phosphor film;

(d) a first barrier film and a second barrier film, wherein the first and second barrier films are each disposed adjacent the remote phosphor film and on opposite sides thereof, and wherein the remote phosphor film is not directly physically coupled to the LGP;

(e) a first reflector film disposed beneath the LGP, wherein the reflector film reflects primary light toward the QDs in the remote phosphor film; and

(f) a second reflector film disposed on top of the remote phosphor film, wherein the second reflector film reflects and recycles a portion of the primary light;

wherein an optical density of the QDs in the remote phosphor film is less than an optical density of the QDs in a remote phosphor film of a BLU that does not include a second reflector film.

2. The BLU of claim 1, wherein the at least two populations of light emitting QDs comprises 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, 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.

3. The BLU of claim 1, wherein the second reflector film comprises a brightness enhancing film (BEF).

4. The BLU of claim 1, wherein the first reflector film is a white film.

5. The BLU of claim 1, wherein the first reflector film comprises a reflective mirror.

6. The BLU of claim 1, wherein the first reflector film comprises scattering features.

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

14. 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.

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

(a) at least one primary light source that emits primary light;

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

(c) a remote phosphor film comprising at least two populations of light emitting quantum dots (QDs), wherein the remote phosphor film is disposed over the LGP, wherein the primary light transmits through the LGP and into the remote phosphor film; and

(d) a barrier film disposed adjacent a top surface of the remote phosphor film and a first reflector film disposed on an opposite side thereof, and wherein the remote phosphor film is not directly physically coupled to the LGP;

wherein an optical density of the QDs in the remote phosphor film is less than an optical density of the QDs in a remote phosphor film of a BLU that does not include a second reflector film.

8. The BLU of claim 7, further comprising a second reflector film disposed on top of the barrier film of the remote phosphor film, wherein the second reflector film reflects and recycles a portion of the primary light.

9. The BLU of claim 7, wherein the second reflector film comprises a BEF.

10. The BLU of claim 7, wherein the first reflector film comprises one or more plastic or polymer barrier film layers and one or more reflective material layers.

11. The BLU of claim 8, wherein the first reflector film includes at least a first plastic or polymer barrier layer disposed directly adjacent to and in direct physical contact with the QD remote phosphor film, and a reflective film layer comprising a metal layer beneath the barrier layer.

12. The BLU of claim 12, wherein the metal layer comprises aluminum.