LIGHT-EMITTING DIODE (LED) DEVICES COMPRISING NANOCRYSTALS

• US 20100155749A1
• Filed: 10/30/2009
• Published: 06/24/2010
• 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: CHEN, Jian, DUBROW, Robert S.
• Application Number:
  US12/609,760
• Publication Number:
  US 20100155749A1
• Time in Patent Office: Days
• US Class Current: 257/89
• CPC Class Codes: C09K 11/025 non-luminescent particle coatings or suspension media
• CPC Class Codes: C09K 11/703 with zinc or cadmium
• CPC Class Codes: C09K 11/881 Chalcogenides
• CPC Class Codes: C09K 11/883 with zinc or cadmium
• CPC Class Codes: G02B 6/0041 provided in the bulk of the light guide
• 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
• 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: Y02B 20/00 Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps

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) an LED;

(b) a light guide optically coupled to the LED; and

(c) a plurality of luminescent nanocrystals dispersed in a region within the light guide, the region extending along a length of the light guide,

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

2. The LED device of claim 1, wherein the luminescent nanocrystals emit blue, green and red light, and the light combines to produce white light.

3. The LED device of claim 2, wherein the LED emits ultraviolet light.

4. The LED device of claim 1, wherein a first portion of light emitted from the LED is down-converted by the nanocrystals, and wherein a second portion of light emitted from the LED and the down-converted light exit a surface of the light guide.

5. The LED device of claim 4, wherein the LED emits blue light.

6. The LED device of claim 5, wherein the first portion of blue light emitted from the LED is down-converted by the luminescent nanocrystals to green light and red light.

7. The LED device of claim 6, wherein the second portion of blue light, the green light and the red light combine to produce white light.

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

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

10. The LED device of claim 1, wherein the light guide comprises one or more reflectors.

11. The LED device of claim 1, wherein the region is a layer of luminescent nanocrystals.

12. The LED device of claim 1, wherein the region has a thickness that varies along the length of the light guide.

13. The LED device of claim 12, wherein the thickness increases from the LED along the length of the light guide.

14. The LED device of claim 13, wherein the thickness increases approximately linearly along the length of the light guide.

16. The white light LED device of claim 12, wherein the light guide comprises one or more reflectors.

17. The white light LED device of claim 12, wherein the region is a layer of CdSe/ZnS luminescent nanocrystals.

18. The white light LED device of claim 12, wherein the region has a thickness that varies along the length of the light guide.

20. The white light LED device of claim 16, wherein the thickness increases approximately linearly along the length of the light guide.

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

(a) a blue light light-emitting LED;

(b) a light guide optically coupled to the LED; and

(c) a plurality of CdSe/ZnS luminescent nanocrystals dispersed in a region within the light guide, the region extending along a length of the light guide,

wherein a first portion of the 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, the green light and red light are emitted from the light guide and combine to produce white light.

19. The white light LED device of claim 15, wherein the thickness increases from the LED along the length of the light guide.

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

(a) an ultraviolet light light-emitting LED;

(b) a light guide optically coupled to the LED; and

(c) a plurality of CdSe/ZnS luminescent nanocrystals dispersed in a region within the light guide, the region extending along a length of the light guide,

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

22. The white light LED device of claim 21, wherein the light guide comprises one or more reflectors.

23. The white light LED device of claim 21, wherein the region is a layer of CdSe/ZnS luminescent nanocrystals.

24. The white light LED device of claim 21, wherein the region has a thickness that varies along the length of the light guide.

25. The white light LED device of claim 24, wherein the thickness increases from the LED along the length of the light guide.

26. The white light LED device of claim 25, wherein the thickness increases approximately linearly along the length of the light guide.

27. A display system, comprising:

(a) a display;

(b) a plurality of light-emitting diodes (LEDs);

(c) a light guide optically coupled the LEDs, wherein the display at least partially encloses the light guide; and

(d) a plurality of luminescent nanocrystals dispersed in a region within the light guide, the region extending along a length of the light guide,

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

28. The display system of claim 27, wherein the luminescent nanocrystals emit blue, green and red light.

29. The display system of claim 28, wherein the LED emits ultraviolet light.

30. The display system of claim 27, wherein a first portion of light emitted from the LED is down-converted by the nanocrystals, and wherein a second portion of light emitted from the LED and the down-converted light exit a surface of the light guide.

31. The display system of claim 30, wherein the LED emits blue light.

32. The display system of claim 31, wherein the first portion of blue light emitted from the LED is down-converted by the luminescent nanocrystals to green light and red light.

33. The display system of claim 32, wherein the second portion of blue light, the green light and the red light combine to produce white light.

34. The display system of claim 27, wherein the luminescent nanocrystals comprise CdSe or ZnS.

35. The display system of claim 27, wherein the luminescent nanocrystals are core/shell luminescent nanocrystals comprising CdSe/ZnS, InP/ZnS, PbSe/PbS, CdSe/CdS, CdTe/CdS or CdTe/ZnS.

36. The display system of claim 27, wherein the light guide comprises one or more reflectors.

37. The display system of claim 27, wherein the region is a layer of luminescent nanocrystals.

38. The display system of claim 27, wherein the region has a thickness that varies along the length of the light guide.

39. The display system of claim 38, wherein the thickness of the region increases from the LED along the length of the light guide.

40. The display system of claim 39, wherein the thickness increases approximately linearly along the length of the light guide.