United States of America As Represented by the Administrator of Nasa

Kunik Lee

Sang Hyouk Choi

Yeonjoon Park

Glen C King

Hyun-Jung Kim

Hyun Jung Kim

Jonathan R Skuza

Systems, methods, and devices of the various embodiments described herein enable an energy conversion system comprising a radioactive element for generating conduction-band electrons in an avalanche cell and generating heat, wherein the conduction-band electrons are provided to an anode to generate avalanche cell power, and the heat is provided to a thermoelectric generator to generate thermoelectric power. In an embodiment, the avalanche cell is irradiated with gamma rays, which excite electrons within the avalanche cell, generating a current. In an additional embodiment, the thermoelectric power and avalanche cell power can comprise a dual power system.

Nuclear thermionic avalanche cells with thermoelectric (NTAC-TE) generator in tandem mode

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

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.

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Troy, MI, United States of America

Kunik Lee