Methods of making quantum dot films

• US 8,213,212 B2
• Filed: 09/23/2011
• Issued: 07/03/2012
• Est. Priority Date: 01/07/2005
• Status: Active Grant

• Current Assignee: InVisage Technologies, Inc. (Apple Inc.)
• Original Assignee: InVisage Technologies, Inc. (Apple Inc.)
• Inventors: Sargent, Edward, Konstantatos, Gerasimos, Levina, Larissa, Howard, Ian, Klem, Ethan J. D., Clifford, Jason
• Primary Examiner(s): Elms, Richard
• Assistant Examiner(s): Byrne, Harry W
• Application Number:
  US13/242,397
• Publication Number:
  US 20120100699A1
• Time in Patent Office: 284 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 7/005 Epitaxial layer growth
• CPC Class Codes: G06F 30/00 Computer-aided design [CAD]
• 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: Y10S 438/962 Quantum dots and lines
• 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

Abstract

In an example embodiment, 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. In another example embodiment, a method of forming a nanocrystalline film includes fabricating nanocrystals having a plurality of first ligands attached to their outer surfaces, exchanging the first ligands for second ligands of a different chemical composition, 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. In another example embodiment, a film includes a network of fused nanocrystals with at least portions of the fused nanocrystals being in direct physical contact with adjacent nanocrystals, the film having substantially no defect states in regions where cores of the nanocrystals are fused.

Claims

1. A method of forming a nanocrystalline film, the method comprising:

fabricating a plurality of nanocrystals, the nanocrystals having a core and an outer surface, a plurality of first ligands having a first length being attached to the outer surface;

exchanging the plurality of first ligands attached to the outer surface of the nanocrystals for a plurality of second ligands having a second length and having a different chemical composition than the plurality of first ligands;

forming a film of ligand-exchanged nanocrystals, at least a portion of the ligand-exchanged nanocrystals being adjacent at least one other ligand-exchanged nanocrystal; and

removing the second ligands attached to the outer surfaces of the nanocrystals of the film of ligand-exchanged nanocrystals so as to bring the outer surfaces of adjacent nanocrystals into closer proximity; and

forming an electrical network of nanocrystals.