Abstract:
A methodology for synthesizing a nanoparticle batch, such as but not limited to a metal chalcogenide nanoparticle batch and further such as but not limited to a metal sulfide nanoparticle batch is predicated upon an expectation and observation that at elevated concentrations of at least one reactant material within a heat-up nanoparticle batch synthesis method, the resulting nucleated batch comprises nanoparticles that may be dimensionally focused to provide a substantially monodisperse nanoparticle batch. The embodied methodology is also applicable to a continuous reactor. The embodied methodology also considers viscosity as a dimensionally focusing result effective variable.
Abstract:
An electro-optic device includes a first electrode, an active layer formed over and electrically connected with the first electrode, a buffer layer formed over and electrically connected with the active layer, and a second electrode formed directly on the buffer layer. The second electrode includes a plurality of nanowires interconnected into a network of nanowires. The buffer layer provides a physical barrier between the active layer and the plurality of nanowires to prevent damage to the active layer while the second electrode is formed.
Abstract:
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.
Abstract:
The present invention provides a novel solution or route for metal phosphide (MP x ) nanomaterials from the thermal decomposition of metal bis[bis(diisopropylphosphino)amide], M[N(PPri 2 ) 2 ] 2 , and/or single-source precursors. Synthetic routes to MP x nanomaterials may be used in energy applications including batteries, semiconductors, magnets, catalyst, lasers, inks, electrocatalysts and photodiodes.
Abstract:
An LED device has a cap containing one or more quantum dot (QD) phosphors. The cap may be sized and configured to be integrated with standard LED packages. The QD phosphor may be held within the well of the LED package, so as to absorb the maximum amount of light emitted by the LED, but arranged in spaced-apart relation from the LED chip to avoid excessive heat that can lead to degradation of the QD phosphor(s). The packages may be manufactured and stored for subsequent assembly onto an LED device.
Abstract:
A semiconductor structure includes an n-channel field effect transistor (NFET) nanowire, the NFET nanowire comprising a film wrapping around a core of the NFET nanowire, the film wrapping configured to provide tensile stress in the NFET nanowire. A method of making a semiconductor structure includes growing a film wrapping around a core of an n-channel field effect transistor (NFET) nanowire of the semiconductor structure, the film wrapping being configured to provide tensile stress in the NFET nanowire.
Abstract:
In certain embodiments, a first semiconductor material is vaporized to generate a vapor phase condensate. The vapor phase condensate is allowed to form nanoparticles. The nanoparticles are annealed to yield nanoparticles or cores. The cores are overcoated by introducing a solution containing second semiconductor material precursors in a coordinating solvent into a suspension of cores at a desired elevated temperature and mixing for a period of time sufficient to cause diffusion of the shell into the core. The diffusion of the shell into the core causes the quantum dots to exhibit a broadened optical emission. The produced quantum dots may be incorporated into a quantum dot based radiation source.
Abstract:
Nanowhiskers are grown in a non-preferential growth direction by regulation of nucleation conditions to inhibit growth in a preferential direction. In a preferred implementation, III-V semiconductor nanowhiskers are grown on an (001) III-V semiconductor substrate surface by effectively inhibiting growth in the preferential B direction. As one example, InP nano-wires were grown by metal-organic vapor phase epitaxy directly on (001) InP substrates. Characterization by scanning electron microscopy and transmission electron microscopy revealed wires with nearly square cross sections and a perfect zincblende crystalline structure that is free of stacking faults.