Abstract: Methods, systems, and apparatuses for annealing semiconductor nanowires and for fabricating electrical devices are provided. Nanowires are deposited on a substrate. A plurality of electrodes is formed. The nanowires are in electrical contact with the plurality of electrodes. The nanowires are doped. A polarized laser beam is applied to the nanowires to anneal at least a portion of the nanowires. The nanowires may be aligned substantially parallel to an axis. The laser beam may be polarized in various ways to modify absorption of radiation of the applied laser beam by the nanowires. For example, the laser beam may be polarized in a direction substantially parallel to the axis or substantially perpendicular to the axis to enable different nanowire absorption profiles.

Abstract: The present invention is directed to systems and methods for nanowire growth. In an embodiment, methods for nanowire growth and doping are provided, including methods for epitaxial vertically oriented nanowire growth including providing a substrate material having one or more nucleating particles deposited thereon in a reaction chamber, introducing an etchant gas into the reaction chamber at a first temperature which gas aids in cleaning the surface of the substrate material, contacting the nucleating particles with at least a first precursor gas to initiate nanowire growth, and heating the alloy droplet to a second temperature, whereby nanowires are grown at the site of the nucleating particles. The etchant gas may also be introduced into the reaction chamber during growth of the wires to provide nanowires with low taper.

Abstract: Methods for forming or patterning nanostructure arrays are provided. The methods involve formation of arrays on coatings comprising nanostructure association groups, formation of arrays in spin-on-dielectrics, solvent annealing after nanostructure deposition, patterning using resist, and/or use of devices that facilitate array formation. Related devices for forming nanostructure arrays are also provided, as are devices including nanostructure arrays (e.g., memory devices).

Abstract: The present invention is directed to methods to harvest, integrate and exploit nanomaterials, and particularly elongated nanowire materials. The invention provides methods for harvesting nanowires that include selectively etching a sacrificial layer placed on a nanowire growth substrate to remove nanowires. The invention also provides methods for integrating nanowires into electronic devices that include placing an outer surface of a cylinder in contact with a fluid suspension of nanowires and rolling the nanowire coated cylinder to deposit nanowires onto a surface. Methods are also provided to deposit nanowires using an ink-jet printer or an aperture to align nanowires. Additional aspects of the invention provide methods for preventing gate shorts in nanowire based transistors. Additional methods for harvesting and integrating nanowires are provided.

Abstract: Methods and systems for depositing nanomaterials onto a receiving substrate and optionally for depositing those materials in a desired orientation, that comprise providing nanomaterials on a transfer substrate and contacting the nanomaterials with an adherent material disposed upon a surface or portions of a surface of a receiving substrate. Orientation is optionally provided by moving the transfer and receiving substrates relative to each other during the transfer process.

Abstract: The present invention generally discloses the use of a nanostructured non-silicon thin film (such as an alumina or aluminum thin film) on a supporting substrate which is subsequently coated with an active layer of a material such as silicon or tungsten. The base, underlying non-silicon material generates enhanced surface area while the active layer assists in incorporating and transferring energy to one or more analytes adsorbed on the active layer when irradiated with a laser during laser desorption of the analyte(s). The present invention provides substrate surfaces that can be produced by relatively straightforward and inexpensive manufacturing processes and which can be used for a variety of applications such as mass spectrometry, hydrophobic or hydrophilic coatings, medical device applications, electronics, catalysis, protection, data storage, optics, and sensors.

Abstract: Porous and/or curved nanofiber bearing substrate materials are provided having enhanced surface area for a variety of applications including as electrical substrates, semipermeable membranes and barriers, structural lattices for tissue culturing and for composite materials, production of long unbranched nanofibers, and the like. A method of producing nanofibers is disclosed including providing a plurality of microparticles or nanoparticles such as carbon black particles having a catalyst material deposited thereon, and synthesizing a plurality of nanofibers from the catalyst material on the microparticles or nanoparticles. Compositions including carbon black particles having nanowires deposited thereon are further disclosed.

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.

Abstract: Methods of doping nanostructures, such as nanowires, are disclosed. The methods provide a variety of approaches for improving existing methods of doping nanostructures. The embodiments include the use of a sacrificial layer to promote uniform dopant distribution within a nanostructure during post-nanostructure synthesis doping. In another embodiment, a high temperature environment is used to anneal nanostructure damage when high energy ion implantation is used. In another embodiment rapid thermal annealing is used to drive dopants from a dopant layer on a nanostructure into the nanostructure. In another embodiment a method for doping nanowires on a plastic substrate is provided that includes depositing a dielectric stack on a plastic substrate to protect the plastic substrate from damage during the doping process.

Abstract: The present invention provides methods for hermetically sealing luminescent nanocrystals, as well as compositions and containers comprising hermetically sealed luminescent nanocrystals. By hermetically sealing the luminescent nanocrystals, enhanced lifetime and luminescence can be achieved.

Abstract: Nanowire dispersion compositions (and uses thereof) are disclosed comprising a plurality of inorganic nanowires suspended in an aqueous or non-aqueous solution comprising at least one low molecular weight and/or low HLB (Hydrophile-Lipophile Balance) value dispersant. Methods of further improving the dispersability of a plurality of inorganic nanowires in an aqueous or non-aqueous solution comprise, for example, oxidizing the surface of the nanowires prior to dispersing the nanowires in the aqueous or non-aqueous solution.

Abstract: A method and apparatus for an electronic substrate having a plurality of semiconductor devices is described. A thin film of nanowires is formed on a substrate. The thin film of nanowires is formed to have a sufficient density of nanowires to achieve an operational current level. A plurality of semiconductor regions are defined in the thin film of nanowires. Contacts are formed at the semiconductor device regions to thereby provide electrical connectivity to the plurality of semiconductor devices. Furthermore, various materials for fabricating nanowires, thin films including p-doped nanowires and n-doped nanowires, nanowire heterostructures, light emitting nanowire heterostructures, flow masks for positioning nanowires on substrates, nanowire spraying techniques for depositing nanowires, techniques for reducing or eliminating phonon scattering of electrons in nanowires, and techniques for reducing surface states in nanowires are described.

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.

Abstract: Methods for forming or patterning nanostructure arrays are provided. The methods involve formation of arrays on coatings comprising nanostructure association groups, formation of arrays in spin-on-dielectrics, solvent annealing after nanostructure deposition, patterning using resist, and/or use of devices that facilitate array formation. Related devices for forming nanostructure arrays are also provided, as are devices including nanostructure arrays (e.g., memory devices). Methods for protecting nanostructures from fusion during high temperature processing are also provided.

Abstract: The present invention is directed to methods to harvest, integrate and exploit nanomaterials, and particularly elongated nanowire materials. The invention provides methods for harvesting nanowires that include selectively etching a sacrificial layer placed on a nanowire growth substrate to remove nanowires. The invention also provides methods for integrating nanowires into electronic devices that include placing an outer surface of a cylinder in contact with a fluid suspension of nanowires and rolling the nanowire coated cylinder to deposit nanowires onto a surface. Methods are also provided to deposit nanowires using an ink-jet printer or an aperture to align nanowires. Additional aspects of the invention provide methods for preventing gate shorts in nanowire based transistors. Additional methods for harvesting and integrating nanowires are provided.

Abstract: Methods, systems, and apparatuses for electronic devices having improved gate structures are described. An electronic device includes at least one nanowire. A gate contact is positioned along at least a portion of a length of the at least one nanowire. A dielectric material layer is between the gate contact and the at least one nanowire. A source contact and a drain contact are in contact with the at least one nanowire. At least a portion of the source contact and/or the drain contact overlaps with the gate contact along the nanowire the length. In another aspect, an electronic device includes a nanowire having a semiconductor core surrounded by an insulating shell layer. A ring shaped first gate region surrounds the nanowire along a portion of the length of the nanowire. A second gate region is positioned along the length of the nanowire between the nanowire and the substrate.

Abstract: This invention provides novel nanofiber enhanced surface area substrates and structures comprising such substrates, as well as methods and uses for such substrates.

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.

Abstract: Matrixes doped with semiconductor nanocrystals are provided. In certain embodiments, the semiconductor nanocrystals have a size and composition such that they absorb or emit light at particular wavelengths. The nanocrystals can comprise ligands that allow for mixing with various matrix materials, including polymers, such that a minimal portion of light is scattered by the matrixes. The matrixes of the present invention can also be utilized in refractive index matching applications. In other embodiments, semiconductor nanocrystals are embedded within matrixes to form a nanocrystal density gradient, thereby creating an effective refractive index gradient. The matrixes of the present invention can also be used as filters and antireflective coatings on optical devices and as down-converting layers. Processes for producing matrixes comprising semiconductor nanocrystals are also provided.

Abstract: Methods of processing nanocrystals to remove excess free and bound organic material and particularly surfactants used during the synthesis process, and resulting nanocrystal compositions, devices and systems that are physically, electrically and chemically integratable into an end application.