LIGHT-EMITTING DIODE (LED) DEVICES COMPRISING NANOCRYSTALS

• US 20100110728A1
• Filed: 10/30/2009
• Published: 05/06/2010
• Est. Priority Date: 03/19/2007
• Status: Abandoned Application

• Current Assignee: Nanosys Incorporated (Shoei Electronic Materials, Inc.)
• Original Assignee: Nanosys Incorporated (Shoei Electronic Materials, Inc.)
• Inventors: Lee, Ernest, Hofler, Hans Jurgen, DUBROW, Robert S., Chen, Jian, Hardev, Veeral D.
• Application Number:
  US12/609,736
• Publication Number:
  US 20100110728A1
• Time in Patent Office: Days
• US Class Current: 362/615
• CPC Class Codes: B32B 2457/206 Organic displays, e.g. OLED
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: C09K 11/025 non-luminescent particle coatings or suspension media
• CPC Class Codes: C09K 11/565 with zinc cadmium
• CPC Class Codes: C09K 11/883 with zinc or cadmium
• CPC Class Codes: G02B 1/02 made of crystals, e.g. rock-salt, semi-conductors G02B1/08 takes precedence
• CPC Class Codes: G02B 1/10 Optical coatings produced by application to, or surface treatment of, optical elements G02B1/08 takes precedence
• CPC Class Codes: G02B 6/0041 provided in the bulk of the light guide
• CPC Class Codes: G02B 6/0068 Arrangements of plural sources, e.g. multi-colour light sources
• 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 2933/0041 relating to wavelength conversion elements
• CPC Class Codes: H01L 33/502 Wavelength conversion materials
• CPC Class Codes: H01L 33/505 characterised by the shape, e.g. plate or foil
• CPC Class Codes: H01L 33/507 the elements being in intimate contact with parts other than the semiconductor body or integrated with parts other than the semiconductor body
• CPC Class Codes: H05B 33/04 Sealing arrangements , e.g. against humidity
• CPC Class Codes: Y02B 20/00 Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps
• CPC Class Codes: Y10S 977/81 Of specified metal or metal alloy composition
• CPC Class Codes: Y10S 977/834 Optical properties of nanomaterial, e.g. specified transparency, opacity, or index of refraction
• CPC Class Codes: Y10S 977/952 Display
• CPC Class Codes: Y10T 156/10 : Methods of surface bonding and/or assembly therefor

Abstract

The present invention provides light-emitting diode (LED) devices comprises compositions and containers of hermetically sealed luminescent nanocrystals. The present invention also provides displays comprising the LED devices. Suitably, the LED devices are white light LED devices.

Claims

1. A light-emitting diode (LED) device, comprising:

(a) a blue-light emitting LED; and

(b) a hermetically sealed container comprising a plurality of luminescent nanocrystals,

wherein the container is placed with respect to the LED to facilitate down-conversion of the luminescent nanocrystals.

2. The LED device of claim 1, wherein the hermetically sealed container is a plastic or glass tube.

3. The LED device of claim 1, wherein the hermetically sealed container is a glass capillary.

4. The LED device of claim 1, wherein the hermetically sealed container is spaced apart from the LED.

5. The LED device of claim 1, wherein the luminescent nanocrystals emit green light and red light.

6. The LED device of claim 1, wherein the luminescent nanocrystals comprise CdSe or ZnS.

7. The LED device of claim 1, wherein the luminescent nanocrystals are core/shell luminescent nanocrystals comprising CdSe/ZnS, InP/ZnS, PbSe/PbS, CdSe/CdS, CdTe/CdS or CdTe/ZnS.

8. The LED device of claim 1, wherein the luminescent nanocrystals are dispersed in a polymeric matrix.

9. A display system, comprising:

(a) a display; and

(b) a plurality of light-emitting diode (LED) devices, the LED devices comprising;

(i) a blue light emitting LED; and

(ii) a hermetically sealed container comprising a plurality of luminescent nanocrystals, wherein the container is placed with respect to the LED to facilitate down-conversion of the luminescent nanocrystals.

10. The display system of claim 9, wherein the hermetically sealed container is a plastic or glass tube.

11. The display system of claim 9, wherein the hermetically sealed container is a glass capillary.

12. The display system of claim 9, wherein the hermetically sealed container is spaced apart from the LED.

13. The display system of claim 9, wherein the luminescent nanocrystals emit green light and red light.

14. The display system of claim 9, wherein the luminescent nanocrystals comprise CdSe or ZnS.

15. The display system of claim 9, wherein the luminescent nanocrystals are core/shell luminescent nanocrystals comprising CdSe/ZnS, InP/ZnS, PbSe/PbS, CdSe/CdS, CdTe/CdS or CdTe/ZnS.

16. The display system of claim 9, wherein the luminescent nanocrystals are dispersed in a polymeric matrix.

17. A light-emitting diode (LED) device, comprising:

(a) an LED;

(b) a hermetically sealed container comprising a plurality of luminescent nanocrystals optically coupled to the LED; and

(c) a light guide optically coupled to the hermetically sealed container,

wherein a first portion of light emitted from the LED is down-converted by the luminescent nanocrystals, and wherein a second portion of light emitted from the LED and the down-converted light from the luminescent nanocrystals are emitted from the light guide.

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29. A white light light-emitting diode (LED) device, comprising:

(a) a blue light light-emitting LED;

(b) a hermetically sealed container comprising a plurality of CdSe/ZnS luminescent nanocrystals optically coupled to the LED; and

(c) a light guide optically coupled the hermetically sealed container,

wherein a first portion of blue light emitted from the LED is down-converted by the CdSe/ZnS luminescent nanocrystals to green light and red light, and wherein a second portion of blue light emitted from the LED, the green light and the red light, are emitted from the light guide and combine to produce white light.

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36. A display system, comprising:

(a) a display;

(b) a plurality of light-emitting diode (LED) devices, the LED devices comprising;

(i) an LED; and

(ii) a hermetically sealed container comprising a plurality of luminescent nanocrystals optically coupled to the LED; and

(c) a light guide optically coupled to the hermetically sealed container, wherein the display at least partially encloses the light guide,

wherein a first portion of light emitted from the LED is down-converted by the luminescent nanocrystals, and wherein a second portion of light emitted from the LED and the down-converted light from the luminescent nanocrystals are emitted from the light guide and displayed on the display.

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48. A composite material, comprising:

(a) a first polymeric material having a first composition;

(b) a second polymeric material having a second composition; and

(c) a plurality of luminescent nanocrystals dispersed in the second polymeric material,

wherein the second polymeric material is dispersed in the first polymeric material.

49. The composite material of claim 48, wherein the first polymeric material comprises an epoxy or a polycarbonate.

50. The composite material of claim 48, wherein the second polymeric material comprises aminosilicone.

51. The composite material of claim 48, wherein the luminescent nanocrystals emit green light and/or red light.

52. The composite material of claim 48, wherein the luminescent nanocrystals comprise CdSe or ZnS.

53. The composite material of claim 48, wherein the luminescent nanocrystals are core/shell luminescent nanocrystals comprising CdSe/ZnS, InP/ZnS, PbSe/PbS, CdSe/CdS, CdTe/CdS or CdTe/ZnS.

54. The composite material of claim 48, further comprising an inorganic layer of SiO₂, TiO₂ or AlO₂ hermetically sealing the composite.

55. The composite material of claim 48, wherein the composite has an optical density of about 0.5 to about 0.9 and a path length of about 50 μ

m to about 200 μ

m.

56. The composite material of claim 55, wherein the composite has an optical density of about 0.8 and a path length of about 100 μ

m.

57. A method of preparing a luminescent nanocrystal composite material, comprising:

(a) dispersing a plurality of luminescent nanocrystals in a first polymeric material to form a mixture of the luminescent nanocrystals and the first polymeric material;

(b) curing the mixture;

(c) generating a particulate from the cured mixture; and

(d) dispersing the particulate in a second polymeric material to generate the composite material.

58. The method of claim 57, wherein the dispersing in (a) comprises dispersing the luminescent nanocrystals in aminosilicone.

59. The method of claim 57, wherein the dispersing in (a) comprises dispersing luminescent nanocrystals comprising CdSe or ZnS.

60. The method of claim 57, wherein the dispersing in (a) comprises dispersing luminescent nanocrystals comprising CdSe/ZnS, InP/ZnS, PbSe/PbS, CdSe/CdS, CdTe/CdS or CdTe/ZnS.

61. The method of claim 57, comprising adding a cross-linker to the mixture prior to the curing in (b).

62. The method of claim 57, wherein the generating a particulate comprises ball milling the cured mixture.

63. The method of claim 57, further comprising forming the composite material into a film.

64. A light-emitting diode (LED) device, comprising:

(a) an LED;

(b) a hermetically sealed container comprising a plurality of luminescent nanocrystals optically coupled to the LED; and

(c) a light guide optically coupled to the hermetically sealed container,

wherein light emitted from the LED is down-converted by the nanocrystals, and exits a surface of the light guide.

68. The LED device of claim 64, wherein the hermetically sealed container is a glass capillary.

69. The LED device of claim 68, wherein the glass capillary has at least one dimension of about 100 μ

m to about 1 mm.

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