Electronic and optoelectronic devices with quantum dot films

• US 8,023,306 B2
• Filed: 05/14/2010
• Issued: 09/20/2011
• Est. Priority Date: 01/07/2005
• Status: Active Grant

• Current Assignee: InVisage Technologies, Inc. (Apple Inc.)
• Original Assignee: InVisage Technologies, Inc. (Apple Inc.)
• Inventors: Konstantatos, Gerasimos, Howard, Ian, Klem, Ethan J. D., Clifford, Jason, Sargent, Edward, Levina, Larissa
• Primary Examiner(s): Elms; Richard
• Assistant Examiner(s): Byrne; Harry W
• Application Number:
  US12/780,420
• Publication Number:
  US 20100314603A1
• Time in Patent Office: 494 Days
• Field of Search: 365/129, 365/161, 365/163, 257/1, 257 14- 25, 257/59, 257/72, 257/250, 257/E29.071, 257/E25.004, 257/E27.083, 257/E27.16, 438/48, 438/197, 438/479, 438/590, 438/962, 428/403, 428/407, 252/301.4, 252/301.6, 977/708, 977/774, 977/775, 977/773, 977/778, 977/759, 977/847, 372/43, 435/472, 424/484, 385/122, 600/425
• US Class Current: 365/129
• 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 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: C30B 29/605 Products containing multiple oriented crystallites, e.g. columnar crystallites
• CPC Class Codes: C30B 7/00 Single-crystal growth from solutions using solvents which are liquid at normal temperature, e.g. aqueous solutions from molten solvents C30B9/00; by normal or gradient freezing C30B11/00; under a protective fluid C30B27/00
• CPC Class Codes: C30B 7/005 Epitaxial layer growth
• CPC Class Codes: H01L 21/02422 Non-crystalline insulating materials, e.g. glass, polymers
• CPC Class Codes: H01L 21/02521 Materials
• CPC Class Codes: H01L 21/02601 Nanoparticles fullerenes H10K85/211
• CPC Class Codes: H01L 21/02628 using solutions
• CPC Class Codes: H01L 27/14601 Structural or functional details thereof
• CPC Class Codes: H01L 29/22 including, apart from doping materials or other impurities, only AIIBVI compounds
• CPC Class Codes: H01L 31/0352 characterised by their shape or by the shapes, relative sizes or disposition of the semiconductor regions
• CPC Class Codes: H10K 10/466 Lateral bottom-gate IGFETs comprising only a single gate
• CPC Class Codes: H10K 10/488 the channel region comprising a layer of composite material having interpenetrating or embedded materials, e.g. a mixture of donor and acceptor moieties, that form a bulk heterojunction
• CPC Class Codes: H10K 30/30 comprising bulk heterojunctions, e.g. interpenetrating networks of donor and acceptor material domains
• CPC Class Codes: H10K 30/35 comprising inorganic nanostructures, e.g. CdSe nanoparticles
• CPC Class Codes: H10K 39/30 Devices controlled by radiation
• CPC Class Codes: H10K 85/114 Poly-phenylenevinylene; 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
• CPC Class Codes: Y10S 977/773 : Nanoparticle, i.e. structure having three dimensions of 100 nm or less
• CPC Class Codes: Y10S 977/774 : Exhibiting three-dimensional carrier confinement, e.g. quantum dots
• CPC Class Codes: Y10T 428/24628 : Nonplanar uniform thickness material
• CPC Class Codes: Y10T 428/24802 : Discontinuous or differential coating, impregnation or bond [e.g., artwork, printing, retouched photograph, etc.]
• CPC Class Codes: Y10T 428/249921 : Web or sheet containing structurally defined element or component

Abstract

Optical and optoelectronic devices and methods of making same. Under one aspect, an optical device includes an integrated circuit an array of conductive regions; and an optically sensitive material over at least a portion of the integrated circuit and in electrical communication with at least one conductive region of the array of conductive regions. Under another aspect, a method of forming a nanocrystalline film includes fabricating a plurality of nanocrystals having a plurality of first ligands attached to their outer surfaces; exchanging the first ligands for second ligands of different chemical composition than the first ligands; forming a film of the ligand-exchanged nanocrystals; removing the second ligands; and fusing the cores of adjacent nanocrystals in the film to form an electrical network of fused nanocrystals. Under another aspect, a film includes a network of fused nanocrystals, the nanocrystals having a core and an outer surface, wherein the core of at least a portion of the fused nanocrystals is in direct physical contact and electrical communication with the core of at least one adjacent fused nanocrystal, and wherein the film has substantially no defect states in the regions where the cores of the nanocrystals are fused.

Claims

1. A film comprising a network of fused nanocrystals, the nanocrystals having a core and an outer surface, wherein the core of at least a portion of the fused nanocrystals is in direct physical contact and electrical communication with the core of at least one adjacent fused nanocrystal, the outer surface including a semiconductor material, the film having substantially no defect states in the regions where the cores of the nanocrystals are fused.

2. The film of claim 1, wherein the outer surface includes at least one defect state.

3. The film of claim 1, wherein the film is substantially inorganic.

4. The film of claim 1, wherein the film is substantially free of ligands on the outer surfaces of the fused nanocrystals.

5. The film of claim 1, wherein the network of fused nanocrystals defines a conductive electrical network.

6. The film of claim 1, wherein the network of fused nanocrystals has an electrical resistance of at least about 25 k-Ohm/square.

7. The film of claim 1, wherein the network of fused nanocrystals has a carrier mobility of between about 0.001 and about 10 cm²/Vs.

8. The film of claim 1, wherein the network of fused nanocrystals has a carrier mobility of between about 0.01 and about 0.1 cm²/Vs.

9. The film of claim 1, wherein the network of fused nanocrystals is optically sensitive.

10. The film of claim 1, wherein the network of fused nanocrystals has a substantially linear responsivity to irradiation in at least a portion of the electromagnetic spectrum.

11. The film of claim 1, wherein the film is disposed on a substrate.

12. The film of claim 11, wherein the substrate is flexible and formed in a non-planar shape.

13. The film of claim 11, wherein the substrate comprises an integrated circuit, at least some components of which are in electrical communication with the film.

14. The film of claim 11, wherein the substrate comprises at least one of a semiconducting organic molecule, a semiconducting polymer, and a crystalline semiconductor.

15. The film of claim 11, wherein the film has an electrical resistance of at least about 25 k-Ohm/square.

16. The film of claim 1, wherein the network of fused nanocrystals includes fused nanocrystals of different compositions.

17. The film of claim 1, wherein the network of fused nanocrystals includes fused nanocrystals of different sizes.

18. The film of claim 1, wherein the fused nanocrystals comprise at least one of PbS, InAs, InP, PbSe, CdS, CdSe, In_xGa_1-xAs, (Cd-Hg)Te, ZnSe(PbS), ZnS(CdSe), ZnSe(CdS), PbO(PbS), and PbSO₄(PbS).

19. The film of claim 1,wherein the film has an optical response to irradiation in at least one of the infrared, ultraviolet, x-ray, and visible regions of the electromagnetic spectrum.

20. The film of claim 19, wherein the optical response of the film is related to a size of the fused nanocrystals in the film.

21. The film of claim 19, wherein the fused nanocrystals have individual properties that vary by less than about 10% from the individual properties of unfused nanocrystals having the same size, shape, and composition as the fused nanocrystals.

22. A device, comprising:

(a) a film comprising a network of fused nanocrystals, the nanocrystals having a core and an outer surface, wherein the core of at least a portion of the fused nanocrystals is in direct physical contact and electrical communication with the core of at least one adjacent fused nanocrystal, the outer surface comprising a semiconductor material, the film having substantially no defect states in the regions where the cores of the nanocrystals are fused; and

(b) first and second electrodes in spaced relation and in electrical communication with first and second portions of the network of fused nanocrystals.

23. The device of claim 22, wherein the film is substantially free of ligands attached to the outer surface of the fused nanocrystals.

24. The device of claim 23, wherein the outer surfaces include at least one defect state.

25. The device of claim 24, wherein the at least one defect state comprises at least one trap state for a hole during operation of the optical device.

26. The device of claim 22, wherein the electrical network of fused nanocrystals provides a plurality of relatively low-resistance electrical paths from the first electrode to the second electrode.

27. The device of claim 26, wherein the film has an electrical resistance of at least about 25 k-Ohm/square.

28. The device of claim 26, wherein the electrical resistance of the film changes in response to irradiation by light.

29. The device of claim 22, wherein the electrical network of fused nanocrystals provides a plurality of electrical paths from the first electrode to the second electrode and wherein at least some of those electrical paths undergo a change in electrical resistance in response to incident light.

30. The device of claim 22, wherein the film has a carrier mobility of between about 0.001 cm²/Vs and about 10 cm²/Vs.

31. The device of claim 22, wherein the film has a carrier mobility of between about 0.01 cm²/Vs and about 0.1 cm²/Vs.

32. The device of claim 22, wherein the fused nanocrystals comprise a plurality of a first type of fused nanocrystals and a plurality of a second type of fused nanocrystals.

33. The device of claim 32, wherein the core of substantially each of the first type of fused nanocrystals is in direct physical contact and electrical communication with the core of another of the first type of fused nanocrystals.

34. The device of claim 33, wherein the core of substantially each of the second type of fused nanocrystals is in direct physical and electrical communication with the core of another of the second type of fused nanocrystals.

35. The device of claim 22, wherein each fused nanocrystal is of a size and composition to absorb at least one of infrared radiation, x-ray radiation, ultraviolet radiation, and visible radiation.

36. The device of claim 22, wherein the first and second electrodes are disposed on a substrate with the film therebetween and are substantially parallel to one another.

37. The device of claim 22, wherein the first and second electrodes are disposed on a substrate with the film therebetween and are interdigitated.

38. The device of claim 22, wherein the first and second electrodes are spaced by about 0.2 μ

m to about 2 μ

m from each other.