Patent application number | Description | Published |
20090057650 | Nanoscale wires and related devices - The present invention relates generally to sub-microelectronic circuitry, and more particularly to nanometer-scale articles, including nanoscale wires which can be selectively doped at various locations and at various levels. In some cases, the articles may be single crystals. The nanoscale wires can be doped, for example, differentially along their length, or radially, and either in terms of identity of dopant, concentration of dopant, or both. This may be used to provide both n-type and p-type conductivity in a single item, or in different items in close proximity to each other, such as in a crossbar array. The fabrication and growth of such articles is described, and the arrangement of such articles to fabricate electronic, optoelectronic, or spintronic devices and components. For example, semiconductor materials can be doped to form n-type and p-type semiconductor regions for making a variety of devices such as field effect transistors, bipolar transistors, complementary inverters, tunnel diodes, light emitting diodes, sensors, and the like. | 03-05-2009 |
20100155698 | Nanoscale wires and related devices - The present invention relates generally to sub-microelectronic circuitry, and more particularly to nanometer-scale articles, including nanoscale wires which can be selectively doped at various locations and at various levels. In some cases, the articles may be single crystals. The nanoscale wires can be doped, for example, differentially along their length, or radially, and either in terms of identity of dopant, concentration of dopant, or both. This may be used to provide both n-type and p-type conductivity in a single item, or in different items in close proximity to each other, such as in a crossbar array. The fabrication and growth of such articles is described, and the arrangement of such articles to fabricate electronic, optoelectronic, or spintronic devices and components. For example, semiconductor materials can be doped to form n-type and p-type semiconductor regions for making a variety of devices such as field effect transistors, bipolar transistors, complementary inverters, tunnel diodes, light emitting diodes, sensors, and the like. | 06-24-2010 |
20100295019 | NANOWIRE PHOTODETECTOR AND IMAGE SENSOR WITH INTERNAL GAIN - A practical ID nanowire photodetector with high gain that can be controlled by a radial electric field established in the ID nanowire. A ID nanowire photodetector device of the invention includes a nanowire that is individually contacted by electrodes for applying a longitudinal electric field which drives the photocurrent. An intrinsic radial electric field to the nanowire inhibits photo-carrier recombination, thus enhancing the photocurrent response. The invention further provides circuits of ID nanowire photodetectors, with groups of photodetectors addressed by their individual ID nanowires electrode contacts. The invention also provides a method for placement of ID nanostructures, including nanowires, with registration onto a substrate. A substrate is patterned with a material, e.g., photoresist, and trenches are formed in the patterning material at predetermined locations for the placement of ID nanostructures. The ID nanostructures are aligned in a liquid suspension, and then transferred into the trenches from the liquid suspension. Removal of the patterning material places the ID nanostructures in predetermined, registered positions on the substrate. | 11-25-2010 |
20110163292 | Nanowire Array-Based Light Emitting Diodes and Lasers - Semiconductor nanowire arrays are used to replace the conventional planar layered construction for fabrication of LEDs and laser diodes. The nanowire arrays are formed from III-V or II-VI compound semiconductors on a conducting substrate. For fabrication of the device, an electrode layer is deposited on the substrate, a core material of one of a p-type and n-type compound semiconductor material is formed on top of the electrode as a planar base with a plurality of nanowires extending substantially vertically therefrom. A shell material of the other of the p-type and n-type compound semiconductor material is formed over an outer surface of the core material so that a p-n junction is formed across the planar base and over each of the plurality of nanowires. An electrode coating is formed an outer surface of the shell material for providing electrical contact to a current source. Heterostructures and superlattices grown along the lengths of the nanowires allow the confinement of photons in the quantum well to enhance the efficiency and as well as color tuning. | 07-07-2011 |
20110253982 | VERTICAL GROUP III-V NANOWIRES ON SI, HETEROSTRUCTURES, FLEXIBLE ARRAYS AND FABRICATION - Embodiments of the invention provide a method for direct heteroepitaxial growth of vertical III-V semiconductor nanowires on a silicon substrate. The silicon substrate is etched to substantially completely remove native oxide. It is promptly placed in a reaction chamber. The substrate is heated and maintained at a growth temperature. Group III-V precursors are flowed for a growth time. Preferred embodiment vertical Group III-V nanowires on silicon have a core-shell structure, which provides a radial homojunction or heterojunction. A doped nanowire core is surrounded by a shell with complementary doping. Such can provide high optical absorption due to the long optical path in the axial direction of the vertical nanowires, while reducing considerably the distance over which carriers must diffuse before being collected in the radial direction. Alloy composition can also be varied. Radial and axial homojunctions and heterojunctions can be realized. Embodiments provide for flexible Group III-V nanowire structures. An array of Group III-V nanowire structures is embedded in polymer. A fabrication method forms the vertical nanowires on a substrate, e.g., a silicon substrate. Preferably, the nanowires are formed by the preferred methods for fabrication of Group III-V nanowires on silicon. Devices can be formed with core/shell and core/multi-shell nanowires and the devices are released from the substrate upon which the nanowires were formed to create a flexible structure that includes an array of vertical nanowires embedded in polymer. | 10-20-2011 |
20110297846 | ELECTRON INJECTION NANOSTRUCTURED SEMICONDUCTOR MATERIAL ANODE ELECTROLUMINESCENCE METHOD AND DEVICE - Embodiments of the invention include methods and devices for producing light by injecting electrons from field emission cathode across a gap into nanostructured semiconductor materials, electrons issue from a separate field emitter cathode and are accelerated by a voltage across a gap towards the surface of the nanostructured material that forms part of the anode. At the nanostructure material, the electrons undergo electron-hole (e-h) recombination resulting in electroluminescent (EL) emission. In a preferred embodiment lighting device, a vacuum enclosure houses a field emitter cathode. The vacuum enclosure also houses an anode that is separated by a gap from said cathode and disposed to receive electrons emitted from the cathode. The anode includes semiconductor light emitting nano structures that accept injection of electrons from the cathode and generate photons in response to the injection of electrons. External electrode contacts permit application of a voltage differential across the anode and cathode to stimulate electron emissions from the cathode and resultant photon emissions from the semiconductor light emitting nanostructures of the anode. Embodiments of the invention also include the usage of nanostructured semiconductor materials as phosphors for conventional planar LED and nanowire array light emitting diodes and CFL. For the use in conventional planar LEDs, the nanostructures may take the form of quantum dots, nanotubes, branched tree-like nanostructure, nanoflower, tetrapods, tripods, axial heterostructures nanowires hetero structures. | 12-08-2011 |
20140103295 | NANOWIRE PHOTODETECTOR AND IMAGE SENSOR WITH INTERNAL GAIN - A 1D nanowire photodetector device includes a nanowire that is individually contacted by electrodes for applying a longitudinal electric field which drives the photocurrent. An intrinsic radial electric field to inhibits photo-carrier recombination, thus enhancing the photocurrent response. Circuits of 1D nanowire photodetectors include groups of photodetectors addressed by their individual 1D nanowire electrode contacts. Placement of 1D nanostructures is accomplished with registration onto a substrate. A substrate is patterned with a material, e.g., photoresist, and trenches are formed in the patterning material at predetermined locations for the placement of 1D nanostructures. The 1D nanostructures are aligned in a liquid suspension, and then transferred into the trenches from the liquid suspension. Removal of the patterning material places the 1D nanostructures in predetermined, registered positions on the substrate. | 04-17-2014 |
20140128972 | ULTRA-HIGH PHOTOSENSITIVITY VERTICAL NANOWIRE ARRAYS FOR RETINAL PROSTHESIS - A prosthetic retina for implantation in an eye having a defective retina is formed from an array of nanowires having a predetermined spatial distribution, density, size and shape implanted in close proximity to the retina. An electrical conductor is formed at a first end of all nanowires in the array of nanowires and placed in contact with a bias source which biases the array. A plurality of electrodes is located on a second end of each of one nanowire or a bundle of nanowires in the array. Each nanowire produces a photocurrent at a corresponding electrode in response to detection of light impinging on the array of nanowires and the photocurrent stimulates one or more neurons adapted for visual perception. In the preferred embodiment, the predetermined spatial distribution mimics a distribution of rods and cones in a normal eye. | 05-08-2014 |
20140291609 | JUNCTIONLESS SEMICONDUCTOR LIGHT EMITTING DEVICES - A junctionless light emitting device comprises a field emitter cathode, and a light emitting semi-conductor material sandwiched between an ohmic contact (OC) that faces the injected electrons and a Schottky contact (SC). The field emitter cathode is configured to inject electrons into the ohmic contact. | 10-02-2014 |