Light emitting devices including semiconductor nanocrystals

• US 20070103068A1
• Filed: 02/15/2006
• Published: 05/10/2007
• Est. Priority Date: 02/16/2005
• Status: Active Grant

• Current Assignee: Massachusetts Institute of Technology
• Original Assignee: Massachusetts Institute of Technology
• Inventors: Bawendi, Moungi, Bulovic, Vladimir, Coe-Sullivan, Seth, Steckel, Jonathan, Caruge, Jean-Michel, Halpert, Jonathan
• Granted Patent: US 8,232,722 B2
• Time in Patent Office: Days
• US Class Current: 313/506
• CPC Class Codes: B65D 2571/00141 glued
• CPC Class Codes: B65D 2571/0045 for hands
• CPC Class Codes: B65D 2571/00574 whereby contents can still be carried after the line has been torn
• CPC Class Codes: B65D 2571/0066 formed from one single sheet
• CPC Class Codes: B65D 2571/00728 the end walls being closed by gluing
• CPC Class Codes: B65D 71/36 having a tubular shape, e.g. tubular wrappers, with end walls
• CPC Class Codes: B65D 81/261 for draining or collecting liquids without absorbing them
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: H01L 2933/0041 relating to wavelength conversion elements
• CPC Class Codes: H01L 33/005 Processes
• CPC Class Codes: H01L 33/06 within the light emitting region, e.g. quantum confinement structure or tunnel barrier
• CPC Class Codes: H01L 33/14 with a carrier transport control structure, e.g. highly-doped semiconductor layer or current-blocking structure
• CPC Class Codes: H01L 33/18 within the light emitting region
• CPC Class Codes: H01L 33/26 Materials of the light emitting region
• CPC Class Codes: H01L 33/42 Transparent materials
• CPC Class Codes: H10K 50/11 characterised by the electroluminescent [EL] layers
• CPC Class Codes: H10K 50/115 comprising active inorganic nanostructures, e.g. luminescent quantum dots
• CPC Class Codes: H10K 50/14 Carrier transporting layers
• CPC Class Codes: H10K 50/18 Carrier blocking layers
• CPC Class Codes: H10K 59/131 : Interconnections, e.g. wiring lines or terminals
• CPC Class Codes: H10K 59/805 : Electrodes

Abstract

A light emitting device includes a semiconductor nanocrystal and a charge transporting layer that includes an inorganic material. The charge transporting layer can be a hole or electron transporting layer. The inorganic material can be an inorganic semiconductor.

Claims

1. A light emitting device comprising:

a first charge transporting layer including a first inorganic material in contact with a first electrode arranged to introduce charge in the first charge transporting layer;

a second electrode; and

a plurality of semiconductor nanocrystals disposed between the first electrode and the second electrode.

2. The light emitting device of claim 1, further comprising a second charge transporting layer in contact with the second electrode, wherein the second electrode is arranged to introduce charge in the second charge transporting layer.

3. The light emitting device of claim 1, wherein the first inorganic material is amorphous or polycrystalline.

4. The light emitting device of claim 1, wherein the first inorganic material is an inorganic semiconductor.

5. The light emitting device of claim 4, wherein the inorganic semiconductor includes a metal chalcogenide.

6. The light emitting device of claim 5, wherein the metal chalcogenide is a mixed metal chalcogenide.

7. The light emitting device of claim 5, wherein the metal chalcogenide includes a zinc oxide, a titanium oxide, a niobium oxide, a zinc sulfide, an indium tin oxide, or a mixture thereof.

8. The light emitting device of claim 1, wherein the second charge transporting layer includes a second inorganic material.

9. The light emitting device of claim 8, wherein the second inorganic material is amorphous or polycrystalline.

10. The light emitting device of claim 8, wherein the second inorganic material is an inorganic semiconductor.

11. The light emitting device of claim 10, wherein the inorganic semiconductor includes a metal chalcogenide.

12. The light emitting device of claim 11, wherein the metal chalcogenide is a mixed metal chalcogenide.

13. The light emitting device of claim 11, wherein the metal chalcogenide includes a zinc oxide, a titanium oxide, a niobium oxide, a zinc sulfide, an indium tin oxide, or a mixture thereof.

14. The light emitting device of claim 1, wherein the first charge transporting layer is a hole transporting layer.

15. The light emitting device of claim 1, wherein the first charge transporting layer is an electron transporting layer.

16. The light emitting device of claim 1, wherein the plurality of semiconductor nanocrystals form a monolayer.

17. The light emitting device of claim 1, wherein the plurality of semiconductor nanocrystals is a substantially monodisperse population of semiconductor nanocrystals.

18. The light emitting device of claim 1, wherein the plurality of semiconductor nanocrystals is arranged in a pattern.

19. The light emitting device of claim 1, wherein the device is transparent.

20. A method of forming a device, comprising:

depositing a first charge transport layer including a first inorganic material over an electrode; and

depositing of plurality of semiconductor nanocrystals over the electrode;

wherein the plurality of semiconductor nanocrystals is in electrical contact with the first charge transport layer.

21. The method of claim 20, wherein depositing the plurality of semiconductor nanocrystals includes depositing the plurality of semiconductor nanocrystals as a monolayer.

22. The method of claim 20, wherein depositing the plurality of semiconductor nanocrystals includes forming a pattern.

23. The method of claim 20, wherein depositing the first inorganic material includes sputtering.

24. The method of claim 23, wherein the first inorganic material is an inorganic semiconductor.

25. The method of claim 24, wherein the inorganic semiconductor includes a metal chalcogenide.

26. The method of claim 25, wherien the metal chalcogenide is a mixed metal chalcogenide.

27. The method of claim 25, wherein the metal chalcogenide includes a zinc oxide, a titanium oxide, a niobium oxide, a zinc sulfide, an indium tin oxide, or a mixture thereof.

28. The method of claim 20, further comprising depositing a second charge transport layer including a second inorganic material over the electrode;

wherein the plurality of semiconductor nanocrystals is in electrical contact with the second charge transport layer.

29. The method of claim 28, wherein depositing the second inorganic material includes sputtering.

30. The method of claim 29, wherein the second inorganic material is an inorganic semiconductor.

31. The method of claim 30, wherein the inorganic semiconductor includes a metal chalcogenide.

32. The method of claim 31, wherien the metal chalcogenide is a mixed metal chalcogenide.

33. The method of claim 31, wherein the metal chalcogenide includes a zinc oxide, a titanium oxide, a niobium oxide, a zinc sulfide, an indium tin oxide, or a mixture thereof.

34. The method of claim 20, wherein the device is transparent.

35. A method of generating light comprising:

providing a device including a first electrode, a second electrode, a first charge transporting layer including a first inorganic material in contact with the first electrode, and a plurality of semiconductor nanocrystals disposed between the first electrode and the second electrode; and

applying a light-generating potential across the first electrode and the second electrode.

36. The method of claim 35, wherein the first inorganic material is amorphous or polycrystalline.

37. The method of claim 36, wherein the first inorganic material is an inorganic semiconductor.

38. The method of claim 37, wherein the inorganic semiconductor includes a metal chalcogenide.

39. The method of claim 38, wherien the metal chalcogenide is a mixed metal chalcogenide.

40. The method of claim 38, wherein the metal chalcogenide includes a zinc oxide, a titanium oxide, a niobium oxide, a zinc sulfide, an indium tin oxide, or a mixture thereof.

41. The method of claim 35, wherein the device further includes a second charge transporting layer including a second inorganic material.

42. The method of claim 41, wherein the second inorganic material is amorphous or polycrystalline.

43. The method of claim 42, wherein the second inorganic material is an inorganic semiconductor.

44. The method of claim 43, wherein the inorganic semiconductor includes a metal chalcogenide.

45. The method of claim 44, wherien the metal chalcogenide is a mixed metal chalcogenide.

46. The method of claim 44, wherein the metal chalcogenide includes a zinc oxide, a titanium oxide, a niobium oxide, a zinc sulfide, an indium tin oxide, or a mixture thereof.

47. The method of claim 35, wherein the pluarlity of semiconductor nanocrystals form a monolayer.

48. The method of claim 35, wherein the plurality of semiconductor nanocrystals is a substantially monodisperse population of semiconductor nanocrystals.

49. The method of claim 35, wherein the plurality of semiconductor nanocrystals is arranged in a pattern.

50. The method of claim 35, wherein the device is transparent.

51. A display including a plurality of light emitting devices, wherein at least one light emitting device comprises:

a first charge transporting layer including a first inorganic material in contact with a first electrode arranged to introduce charge in the first charge transporting layer;

a second electrode; and

a plurality of semiconductor nanocrystals disposed between the first electrode and the second electrode.

52. The display of claim 51, further comprising a second charge transporting layer in contact with the second electrode, wherein the second electrode is arranged to introduce charge in the second charge transporting layer.

53. The display of claim 51, wherein the first inorganic material is amorphous or polycrystalline.

54. The display of claim 51, wherein the first inorganic material is an inorganic semiconductor.

55. The display of claim 54, wherein the inorganic semiconductor includes a metal chalcogenide.

56. The display of claim 55, wherein the metal chalcogenide is a mixed metal chalcogenide.

57. The display of claim 55, wherein the metal chalcogenide includes a zinc oxide, a titanium oxide, a niobium oxide, a zinc sulfide, an indium tin oxide, or a mixture thereof.

58. The display of claim 51, wherein the second charge transporting layer includes a second inorganic material.

59. The display of claim 58, wherein the second inorganic material is amorphous or polycrystalline.

60. The display of claim 58, wherein the second inorganic material is an inorganic semiconductor.

61. The display of claim 60, wherein the inorganic semiconductor includes a metal chalcogenide.

62. The display of claim 61, wherein the metal chalcogenide is a mixed metal chalcogenide.

63. The display of claim 61, wherein the metal chalcogenide includes a zinc oxide, a titanium oxide, a niobium oxide, a zinc sulfide, an indium tin oxide, or a mixture thereof.

64. The display of claim 51, wherein the first charge transporting layer is a hole transporting layer.

65. The display of claim 51, wherein the first charge transporting layer is an electron transporting layer.

66. The display of claim 51, wherein the plurality of semiconductor nanocrystals form a monolayer.

67. The display of claim 51, wherein the plurality of semiconductor nanocrystals is a substantially monodisperse population of semiconductor nanocrystals.

68. The display of claim 51, wherein the plurality of semiconductor nanocrystals is arranged in a pattern.

69. The display of claim 51, wherein the device is transparent.