United States of America As Represented by the Administrator of Nasa

National Institute of Aerospace Associates

The United States of America As Represented by the Administrator of the

Yeonjoon Park

Sang Hyouk Choi

Glen C King

James R Elliott

Jae-Woo Kim

Sang-Hyon Chu

Peter T Lillehei

Kunik Lee

Diane M Stoakley

Hyun-Jung Kim

Hyun Jung Kim

Albert L Dimarcantonio

Noel A Talcott

Jonathan R Skuza

Methods and systems that enable growing a SiGe film at relative high temperature resulting in single crystalline properties and imparting twin crystal structures and/or dislocation to the SiGe film through either in-situ or ex-situ electron-beam irradiation. The various embodiments may maintain (or increase) the Seeback coefficient and electrical conductivity of thermoelectric materials and simultaneously decrease the thermal conductivity of the thermoelectric materials.

Growth method of highly twinned SiGe alloy on the basal plane of trigonal substrate under electron beam irradiation

An electronic device includes a trigonal crystal substrate defining a (0001) C-plane. The substrate may comprise Sapphire or other suitable material. A plurality of rhombohedrally aligned SiGe (111)-oriented crystals are disposed on the (0001) C-plane of the crystal substrate. A first region of material is disposed on the rhombohedrally aligned SiGe layer. The first region comprises an intrinsic or doped Si, Ge, or SiGe layer. The first region can be layered between two secondary regions comprising n+doped SiGe or n+doped Ge, whereby the first region collects electrons from the two secondary regions.

High mobility transport layer structures for rhombohedral Si/Ge/SiGe devices

An X-ray defraction (XRD) characterization method for sigma=3 twin defects in cubic semiconductor (100) wafers includes a concentration measurement method and a wafer mapping method for any cubic tetrahedral semiconductor wafers including GaAs (100) wafers and Si (100) wafers. The methods use the cubic semiconductor's (004) pole figure in order to detect sigma=3/{111} twin defects. The XRD methods are applicable to any (100) wafers of tetrahedral cubic semiconductors in the diamond structure (Si, Ge, C) and cubic zinc-blend structure (InP, InGaAs, CdTe, ZnSe, and so on) with various growth methods such as Liquid Encapsulated Czochralski (LEC) growth, Molecular Beam Epitaxy (MBE), Organometallic Vapor Phase Epitaxy (OMVPE), Czochralski growth and Metal Organic Chemical Vapor Deposition (MOCVD) growth.

X-ray diffraction (XRD) characterization methods for sigma=3 twin defects in cubic semiconductor (100) wafers

One aspect of the present invention is a double sided hybrid crystal structure including a trigonal Sapphire wafer containing a (0001) C-plane and having front and rear sides. The Sapphire wafer is substantially transparent to light in the visible and infrared spectra, and also provides insulation with respect to electromagnetic radio frequency noise. A layer of crystalline Si material having a cubic diamond structure aligned with the cubic &#x3c;111&#x3e; direction on the (0001) C-plane and strained as rhombohedron to thereby enable continuous integration of a selected (SiGe) device onto the rear side of the Sapphire wafer. The double sided hybrid crystal structure further includes an integrated III-Nitride crystalline layer on the front side of the Sapphire wafer that enables continuous integration of a selected III-Nitride device on the front side of the Sapphire wafer.

Method of fabricating double sided Si(Ge)/Sapphire/III-nitride hybrid structure

An integrated hybrid crystal Light Emitting Diode ('LED') display device that may emit red, green, and blue colors on a single wafer. The various embodiments may provide double-sided hetero crystal growth with hexagonal wurtzite III-Nitride compound semiconductor on one side of (0001) c-plane sapphire media and cubic zinc-blended III-V or II-VI compound semiconductor on the opposite side of c-plane sapphire media. The c-plane sapphire media may be a bulk single crystalline c-plane sapphire wafer, a thin free standing c-plane sapphire layer, or crack-and-bonded c-plane sapphire layer on any substrate. The bandgap energies and lattice constants of the compound semiconductor alloys may be changed by mixing different amounts of ingredients of the same group into the compound semiconductor. The bandgap energy and lattice constant may be engineered by changing the alloy composition within the cubic group IV, group III-V, and group II-VI semiconductors and within the hexagonal III-Nitrides.

Integrated multi-color light emitting device made with hybrid crystal structure

Double sided Si(Ge)/Sapphire/III-nitride hybrid structure

Metal and semiconductor nanoshells, particularly transition metal nanoshells, are fabricated using dendrimer molecules. Metallic colloids, metallic ions or semiconductors are attached to amine groups on the dendrimer surface in stabilized solution for the surface seeding method and the surface seedless method, respectively. Subsequently, the process is repeated with additional metallic ions or semiconductor, a stabilizer, and NaBHto increase the wall thickness of the metallic or semiconductor lining on the dendrimer surface. Metallic or semiconductor ions are automatically reduced on the metallic or semiconductor nanoparticles causing the formation of hollow metallic or semiconductor nanoparticles. The void size of the formed hollow nanoparticles depends on the dendrimer generation. The thickness of the metallic or semiconductor thin film around the dendrimer depends on the repetition times and the size of initial metallic or semiconductor seeds.

Fabrication of metallic hollow nanoparticles

A spectrometer that includes a grating that disperses light via Fresnel diffraction according to wavelength onto a sensing area that coincides with an optical axis plane of the grating. The sensing area detects the dispersed light and measures the light intensity associated with each wavelength of the light. Because the spectrometer utilizes Fresnel diffraction, it can be miniaturized and packaged as an integrated circuit.

Linear Fresnel spectrometer chip with gradient line grating

Disclosed is a system and method for characterizing optical materials, using steps and equipment for generating a coherent laser light, filtering the light to remove high order spatial components, collecting the filtered light and forming a parallel light beam, splitting the parallel beam into a first direction and a second direction wherein the parallel beam travelling in the second direction travels toward the material sample so that the parallel beam passes through the sample, applying various physical quantities to the sample, reflecting the beam travelling in the first direction to produce a first reflected beam, reflecting the beam that passes through the sample to produce a second reflected beam that travels back through the sample, combining the second reflected beam after it travels back though the sample with the first reflected beam, sensing the light beam produced by combining the first and second reflected beams, and processing the sensed beam to determine sample characteristics and properties.

Smart optical material characterization system and method

A lock-in imaging system is configured for detecting a disturbance in air. The system includes an airplane, an interferometer, and a telescopic imaging camera. The airplane includes a fuselage and a pair of wings. The airplane is configured for flight in air. The interferometer is operatively disposed on the airplane and configured for producing an interference pattern by splitting a beam of light into two beams along two paths and recombining the two beams at a junction point in a front flight path of the airplane during flight. The telescopic imaging camera is configured for capturing an image of the beams at the junction point. The telescopic imaging camera is configured for detecting the disturbance in air in an optical path, based on an index of refraction of the image, as detected at the junction point.

Lock-in imaging system for detecting disturbances in fluid

Provided is a method for measuring multi-point interferometric angle changes beginning with an interferometric device capable of measuring at least one main point and at least one reference point. The method includes recording interferometric intensity changes on two or more spots using the main point and the reference point, and determining a sequence having a plurality of peak, local maximas and a plurality of valley, local minimas. The method includes sampling a first, partial sequence and comparing it to a neighboring, partial sequence using a perturbation analysis and additional calculation(s) to compile all phase angle changes for all measured points. Also provided is a computer implemented method to enable nanometer resolution sensitivity in a noisy signal and for characterization of a material in an interferometric device.

Multi-point interferometric phase change detection method

Provided is a method of enhancing thermoelectric performance by surrounding crystalline semiconductors with nanoparticles by contacting a bismuth telluride material with a silver salt under a substantially inert atmosphere and a temperature approximately near the silver salt decomposition temperature; and recovering a metallic bismuth decorated material comprising silver telluride crystal grains.

Method of creating micro-scale silver telluride grains covered with bismuth nanoparticles

A new fabrication method for nanovoids-imbedded bismuth telluride (Bi&#x2014;Te) material with low dimensional (quantum-dots, quantum-wires, or quantum-wells) structure was conceived during the development of advanced thermoelectric (TE) materials. Bismuth telluride is currently the best-known candidate material for solid-state TE cooling devices because it possesses the highest TE figure of merit at room temperature. The innovative process described here allows nanometer-scale voids to be incorporated in Bi&#x2014;Te material. The final nanovoid structure such as void size, size distribution, void location, etc. can be also controlled under various process conditions.

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Yorktown, VA, United States of America

Yeonjoon Park