Nanostructure and nanocomposite based compositions and photovoltaic devices

• US 6,878,871 B2
• Filed: 09/04/2003
• Issued: 04/12/2005
• Est. Priority Date: 09/05/2002
• Status: Expired due to Fees

• Current Assignee: Nanosys Incorporated (Shoei Electronic Materials, Inc.)
• Original Assignee: Nanosys Incorporated (Shoei Electronic Materials, Inc.)
• Inventors: Chow, Calvin, Parce, J. Wallace, Meisel, Andreas, Empedocles, Stephen, Buretea, Mihai A., Scher, Erik
• Primary Examiner(s): DIAMOND, ALAN D
• Application Number:
  US10/656,802
• Publication Number:
  US 20040118448A1
• Time in Patent Office: 586 Days
• Field of Search: 136/252, 136/260, 136/262, 136/264, 136/265, 136/255, 136/256, 136/263, 257/466, 257/465, 257/441, 257/440, 257/461
• US Class Current: 136/252
• CPC Class Codes: B82Y 10/00 Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
• 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 31/0384 including other non-monocrystalline materials, e.g. semiconductor particles embedded in an insulating material H01L31/0392 takes precedence
• CPC Class Codes: H01L 31/04 adapted as photovoltaic [PV] conversion devices testing thereof during manufacture H01L22/00; testing thereof after manufacture H02S50/10
• CPC Class Codes: H10K 30/10 comprising heterojunctions between organic semiconductors and inorganic semiconductors
• CPC Class Codes: H10K 30/151 the wide bandgap semiconductor comprising titanium oxide, e.g. TiO2
• CPC Class Codes: H10K 30/35 comprising inorganic nanostructures, e.g. CdSe nanoparticles
• CPC Class Codes: H10K 30/50 Photovoltaic [PV] devices
• CPC Class Codes: H10K 85/113 Heteroaromatic compounds comprising sulfur or selene, e.g. polythiophene
• CPC Class Codes: H10K 85/1135 Polyethylene dioxythiophene [PEDOT]; Derivatives thereof
• CPC Class Codes: Y02E 10/549 Organic PV cells
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product

Abstract

Nanocomposite photovoltaic devices are provided that generally include semiconductor nanocrystals as at least a portion of a photoactive layer. Photovoltaic devices and other layered devices that comprise core-shell nanostructures and/or two populations of nanostructures, where the nanostructures are not necessarily part of a nanocomposite, are also features of the invention. Varied architectures for such devices are also provided including flexible and rigid architectures, planar and non-planar architectures and the like, as are systems incorporating such devices, and methods and systems for fabricating such devices. Compositions comprising two populations of nanostructures of different materials are also a feature of the invention.

Claims

1. A photovoltaic device, comprising:

a first electrode layer;

a second electrode layer; and

a first photoactive layer disposed between the first and second electrode layers, wherein the photoactive layer is disposed in at least partial electrical contact with the first electrode along a first plane, and in at least partial electrical contact with the second electrode along a second plane, and wherein the photoactive layer comprises a first inorganic material and a second inorganic material different from the first inorganic material, which first and second inorganic materials exhibit a type II band offset energy profile, and wherein the photoactive layer comprises a first population of nanostructures comprising nanorods comprising the first inorganic material which are not grown from any layer in the photovoltaic device and a second population of nanostructures comprising the second inorganic material, and wherein some of the nanorods of the photoactive layer do not directly contact any other layer in the photovoltaic device.

2. The photovoltaic device of claim 1, wherein the nanostructures comprise at least a portion that is comprised of a semiconductor selected from Group II-VI, Group III-V or Group IV semiconductors or alloys thereof.

3. The photovoltaic device of claim 1, wherein the population of nanostructures comprises nanorods that comprise one or more of:

CdSe, CdTe, InP, InAs, CdS, ZnS, ZnSe, ZnTe, HgTe, GaN, GaP, GaAs, GaSb, InSb, Si, Ge, AlAs, AlSb, PbSe, PbS, or PbTe.

4. The photovoltaic device of claim 1, wherein the nanostructures comprise:

a single-crystal nanostructure, a double-crystal nanostructure, a polycrystalline nanostructure, or an amorphous nanostructure.

5. The photovoltaic device of claim 1, wherein the population of nanorods comprises a core of first inorganic material and a shell of another inorganic material.

6. The photovoltaic device of claim 9, wherein the core comprises CdSe and the shell comprises CdTe.

7. The photovoltaic device of claim 9, wherein the core comprises InP and the shell comprises GaAs.

8. The photovoltaic device of claim 1, wherein the photoactive layer comprises nanorods disposed in a conductive polymer matrix, and wherein the nanorods are coupled to the polymer matrix.

9. The photovoltaic device of claim 8, wherein the nanorods are coupled to the polymer matrix via a covalent chemical linkage.

10. The photovoltaic device of claim 9, wherein the chemical linkage comprises a ligand coupled at a first position to an outer surface of the nanorod and at a second position to the polymer matrix.

11. The photovoltaic device of claim 8, wherein the nanorods are electrically coupled to the polymer matrix.

12. The photovoltaic device of claim 1, wherein the population of nanostructures is predominantly positioned closer to the first electrode than to the second electrode.

13. The photovoltaic device of claim 1, further comprising a hole or electron blocking layer disposed between the photoactive layer and the first or second electrode.

14. The photovoltaic device of claim 1, further comprising a hole blocking layer disposed between the photoactive layer and the first electrode and an electron blocking layer disposed between the photoactive layer and the second electrode.

15. The photovoltaic device of claim 1, wherein at least one of the first and second electrodes are flexible.

16. The photovoltaic device of claim 15, wherein the first and second electrodes and the photoactive layer are flexible.

17. The photovoltaic device of claim 1, wherein at least one of the first and second electrodes comprises a transparent conductive layer.

18. The photovoltaic device of claim 1, wherein the device comprises a transparent support layer at least partially covering the first or second electrode, or at least partially covering the photoactive layer, or at least partially covering a combination thereof.

19. The photovoltaic device of claim 1, wherein at least one of the electrodes comprises aluminum.

20. The photovoltaic device of claim 1, wherein the photoactive layer is hermetically sealed.

21. The photovoltaic device of claim 20, the device comprising at least one sealing layer in addition to the first and second electrodes.

22. The photovoltaic device of claim 21, wherein the device comprises at least first and second sealing layers, the photoactive layer and first and second electrodes being sandwiched between the first and second sealing layers.

23. The photovoltaic device of claim 1, wherein the overall device comprises a non-planar architecture.

24. The photovoltaic device of claim 1, wherein the device comprises a convex architecture.

25. The photovoltaic device of claim 1, wherein the first electrode layer, the photoactive layer and the second electrode layer are oriented in a coiled architecture.

26. The photovoltaic device of claim 1, wherein the first electrode layer, the photoactive layer and the second electrode layer are oriented in a reciprocating stacked architecture.

27. The photovoltaic device of claim 1, wherein the first and second populations of nanostructures in the photoactive layer have a different absorption spectrum.

28. The photovoltaic device of claim 27, wherein the first and second populations nanostructures comprise different compositions.

29. The photovoltaic device of claim 27, wherein the first and second populations of nanostructures comprise nanocrystals having different size distributions.

30. The photovoltaic device of claim 1, wherein the nanostructures in the photoactive layer collectively comprise more than two inorganic materials.

31. The photovoltaic device of claim 1, wherein the nanostructures in the photoactive layer collectively comprise at least two inorganic materials, wherein the nanostructures comprise a core of the first inorganic material and a shell of the second inorganic material.

32. The photovoltaic device of claim 1, wherein the photoactive layer comprises more than two types of nanostructures.

33. The photovoltaic device of claim 1, wherein the photoactive layer comprises fused, partially fused, and/or sintered nanorods.

34. The photovoltaic device of claim 31, wherein the cores of at least two adjacent nanostructures in the photoactive layer are in at least partial electrical contact, and wherein the shells of the at least two adjacent nanostructures, or at least two additional nanostructures, are in at least partial direct electrical contact.

35. The photovoltaic device of claim 1, wherein the photoactive layer comprises at least two active sublayers.

36. The photovoltaic device of claim 1, wherein the photoactive layer comprises at least two active sublayers, wherein each of the active sublayers comprises a plurality of nanorods of at least one nanocrystal type.

37. The photovoltaic device of claim 1, wherein the photoactive layer comprises at least two sublayers, wherein at least one of the at least two sublayers comprises an n-type sublayer and at least one of the two sublayers comprises a p-type sublayer.

38. The photovoltaic device of claim 1, wherein the photoactive layer comprises at least two sublayers, wherein at least one of the at least two sublayers comprises an n-type sublayer and at least one of the two sublayers comprises a p-type sublayer, wherein the photoactive layer comprises a junction between the p-type sublayer and the n-type sublayer.

39. The photovoltaic device of claim 1, wherein the photoactive layer comprises at least one sublayer comprising a blend of p and n nanorods.

40. The photovoltaic device of claim 1, wherein the device comprises at least a second photoactive layer.

41. The photovoltaic device of claim 1, further comprising:

a third electrode layer;

a fourth electrode layer; and

a second photoactive layer disposed between the third and fourth electrode layers, wherein the second photoactive layer is disposed in at least partial electrical contact with the third electrode along a third plane, and in at least partial electrical contact with the fourth electrode along a fourth plane, and wherein the second photoactive layer exhibits a type II band offset energy profile, and comprises a second population of nanostructures each having at least one elongated section oriented predominantly normal to at least the third plane, and having a different absorption spectrum from the first population of nanostructures, wherein the third electrode layer, fourth electrode layer and second photoactive layer are attached to, but electrically insulated from the first electrode layer, second electrode layer and first photoactive layer.

42. A photovoltaic device, comprising:

a first electrode layer;

a second electrode layer; and

,

a first photoactive layer disposed between the first and second electrode layers, wherein the photoactive layer is disposed in at least partial electrical contact with the first electrode along a first plane and in at least partial electrical contact with the second electrode along a second plane, wherein the photoactive layer comprises a first inorganic material and a second inorganic material different from the first inorganic material, which first and second inorganic materials exhibit a type II band offset energy profile, and wherein the photoactive layer comprises a first population of nanostructures, comprising nanotetrapods comprising the first inorganic material which are not grown from any layer in the photovoltaic device and a second population of nanostructures comprising the second inorganic material, and wherein some of the nanotetrapods of the photoactive layer do not directly contact any other layer in the photovoltaic device.

43. The photovoltaic device of claim 42, wherein the first and second population of nanostructures comprise:

a single-crystal nanostructure, a double-crystal nanostructure, a polycrystalline nanostructure, or an amorphous nanostructure.

44. The photovoltaic device of claim 42, wherein the first inorganic material is a semiconductor and wherein the second inorganic material is a semiconductor.

45. The photovoltaic device of claim 42, wherein the first inorganic material comprises a first semiconductor selected from the group consisting of:

a Group II-VI semiconductor, a Group III-V semiconductor, a Group IV semiconductor, and an alloy thereof, and wherein the second inorganic material comprises a second semiconductor, different from the first semiconductor, selected from the group consisting of;

a Group II-VI semiconductor, a Group III-V semiconductor, a Group IV semiconductor, and an alloy thereof.

46. The photovoltaic device of claim 42, wherein the first population of nanotetrapods comprises a core of the first inorganic material and a shell of the second inorganic material.

47. The photovoltaic device of claim 46, wherein the core comprises CdSe and the shell comprises CdTe.

48. The photovoltaic device of claim 46, wherein the core comprises InP and the shell comprises GaAs.

49. The photovoltaic device of claim 46, wherein the nanotetrapods are fused, partially fused, and/or sintered.

50. The photovoltaic device of claim 46, wherein the cores of at least two adjacent nanotetrapods are in at least partial direct electrical contact and wherein the shells of at least two adjacent nanotetrapods are in at least partial direct electrical contact.

51. The photovoltaic device of claim 46, wherein the cores of one or more nanotetrapods are in at least partial direct electrical contact with the first electrode layer or the second electrode layer.

52. The photovoltaic device of claim 42, wherein the first inorganic material comprises CdSe and the second inorganic material comprises CdTe, the first inorganic material comprises CdS and the second inorganic material comprises CdTe, or the first inorganic material comprises CdS and the second inorganic material comprises ZnSe.

53. The photovoltaic device of claim 42, wherein adjacent nanostructures from the first and second population are in at least partial direct electrical contact with each other.

54. The photovoltaic device of claim 42, wherein the nanotetrapods of the first population and the nanostructures of the second population are intermixed in the photoactive layer.

55. The photovoltaic device of claim 42, wherein the photoactive layer comprises at least a first sublayer and a second sublayer, wherein the first sublayer comprises the first population of nanotetrapods and the second sublayer comprises the second population of nanotetrapods.

56. The photovoltaic device of claim 42, wherein the nanostructures of the first and/or second populations are fused, partially fused, and/or sintered.

57. The photovoltaic device of claim 42, wherein the photoactive layer comprises at least two active sublayers.

58. The photovoltaic device of claim 42, wherein the photoactive layer comprises at least two active sublayers, wherein each of the active sublayers comprises a plurality of nanostructures of at least one nanocrystal type.

59. The photovoltaic device of claim 42, wherein the photoactive layer comprises at least two sublayers, wherein at least one of the at least two sublayers comprises an n-type sublayer and at least one of the two sublayers comprises a p-type sublayer.

60. The photovoltaic device of claim 42, wherein the photoactive layer comprises at least two sublayers, wherein at least one of the at least two sublayers comprises an n-type sublayer and at least one of the two sublayers comprises a p-type sublayer, wherein the photoactive layer comprises a junction between the p-type sublayer and the n-type sublayer.

61. The photovoltaic device of claim 42, wherein the photoactive layer comprises at least one sublayer comprising a blend of p and n nanotetrapods.

62. The photovoltaic device of claim 42, wherein the photoactive layer further comprises a conductive polymer.

63. The photovoltaic device of claim 42, wherein the photoactive layer is free of conductive polymer.

64. The photovoltaic device of claim 42, wherein the photoactive layer further comprises a nonconductive polymer.

65. The photovoltaic device of claim 42, wherein the nanostructures of the first population each has at least one elongated section oriented predominantly normal to at least the first plane.

66. The photovoltaic device of claim 42, further comprising a hole or electron blocking layer disposed between the photoactive layer and the first or second electrode layer.

67. The photovoltaic device of claim 42, further comprising a hole blocking layer disposed between the photoactive layer and the first electrode layer and an electron blocking layer disposed between the photoactive layer and the second electrode layer.

68. The photovoltaic device of claim 42, wherein at least one of the first and second electrodes layers are flexible.

69. The photovoltaic device of claim 68, wherein the first and second electrodes and the photoactive layer are flexible.

70. The photovoltaic device of claim 42, wherein at least one of the first and second electrodes layers comprises a transparent conductive layer.

71. The photovoltaic device of claim 42, wherein at least one of the electrodes comprises aluminum.

72. The photovoltaic device of claim 42, wherein the photoactive layer is hermetically sealed.

73. The photovoltaic device of claim 72, the device comprising at least one sealing layer in addition to the first and second electrodes layers.

74. The photovoltaic device of claim 73, wherein the device comprises at least first and second sealing layers, the photoactive layer and first and second electrodes layers being sandwiched between the first and second sealing layers.

75. The photovoltaic device of claim 42, wherein the overall device comprises a non-planar architecture.

76. The photovoltaic device of claim 42, wherein the device comprises a convex architecture.

77. The photovoltaic device of claim 42, wherein the first electrode layer, the photoactive layer and the second electrode layer are oriented in a coiled architecture.

78. The photovoltaic device of claim 42, wherein the first electrode layer, the photoactive layer and the second electrode layer are oriented in a reciprocating stacked architecture.

79. The photovoltaic device of claim 42, wherein the first and second population of nanostructures have a different absorption spectrum.

80. The photovoltaic device of claim 79, wherein the first and second populations of nanostructures comprise different compositions.

81. The photovoltaic device of claim 79, wherein the first and second population of nanostructures have different size distributions.

82. The photovoltaic device of claim 42, wherein the device comprises at least a second photoactive layer.

83. The photovoltaic device of claim 42, further comprising:

a third electrode layer;

a fourth electrode layer; and

,

a second photoactive layer disposed between the third and fourth electrode layers, wherein the second photoactive layer is disposed in at least partial electrical contact with the third electrode along a third plane and in at least partial electrical contact with the fourth electrode along a fourth plane, wherein the second photoactive layer comprises a second population of nanostructures having a different absorption spectrum from the first population of nanotetrapods, and wherein the third electrode layer, fourth electrode layer and second photoactive layer are attached to, but electrically insulated from, the first electrode layer, second electrode layer and first photoactive layer.