Abstract: Systems, methods, and devices of the various embodiments may provide a portable power system for powering small devices that may be small, may be compact, may provide continuous power, and may be lightweight enough for an astronaut to carry. Various embodiments may provide a compact, thermionic-based cell that provides increased energy density and that more efficiently uses a heat source, such as a Pu-238 heat source. Nanometer scale emitters, spaced tightly together, in various embodiments convert a larger amount of heat into usable electricity than in current thermoelectric technology. The emitters of the various embodiments may be formed from various materials, such as copper (Cu), silicon (Si), silicon-germanium (SiGe), and lanthanides. Various embodiments may be added to regenerative thermionic cells with multiple layers to enhance the energy conversion efficiency of the regenerative thermionic cells.

Abstract: Various aspects include electric generators configured to boost electrical output by leveraging electron avalanche generated by a high energy photon radiation source. In various aspects, an electric generator includes a stator and a rotor positioned within the stator, wherein the stator and rotor are configured to generate electric current when the rotor is rotated, and a high energy photon source (e.g., a gamma ray source) positioned and configured to irradiate at least a portion of conductors in the rotor or stator. In some aspects, the stator generates a magnetic field when the electric generator is operating, and the rotor includes armature windings configured to generate electric current when the rotor is rotated. In some aspects, the high energy photon source includes cobalt-60 and/or cesium-137.

Abstract: Various embodiments provide Molten Target Sputtering (MTS) methods and devices. The various embodiments may provide increases in the kinetic energy, increases in the energy latency, and/or increases in the flux density of molecules for better crystal formation at low temperature operation. The various embodiment MTS methods and devices may enable the growth of a single crystal Si1-xGex film on a substrate heated to less than about 500° C. The various embodiment MTS methods and devices may provide increases in the kinetic energy, increases in the energy latency, and/or increases in the flux density of molecules without requiring the addition of extra systems.

Abstract: Systems, methods, and devices of the various embodiments provide for microfabrication of devices, such as semiconductors, thermoelectric devices, etc. Various embodiments may include a method for fabricating a device, such as a semiconductor (e.g., a silicon (Si)-based complementary metal-oxide-semiconductor (CMOS), etc.), thermoelectric device, etc., using a mask. In some embodiments, the mask may be configured to allow molecules in a deposition plume to pass through one or more holes in the mask. In some embodiments, molecules in a deposition plume may pass around the mask. Various embodiments may provide thermoelectric devices having metallic junctions. Various embodiments may provide thermoelectric devices having metallic junctions rather than junctions formed from semiconductors.

Abstract: A method of forming an epitaxial layer on a substrate such as a sapphire wafer that does not readily absorb thermal radiation. The method includes coating a first side surface of the substrate with an energy-absorbing opaque material. The opaque material forms a thermally absorptive coating on the substrate. The coated substrate may be heated to remove contaminants from the thermally absorptive coating. The coated substrate is positioned in a vacuum deposition chamber and heated by directing radiative energy onto the thermally absorptive coating. An epitaxial layer such as GaN or SiGe is formed on a second side surface of the substrate opposite the thermally absorptive coating.

Abstract: The present disclosure is directed to a nuclear thermionic avalanche cell (NTAC) systems and related methods of generating energy comprising a radioisotope core, a plurality of thin-layered radioisotope sources configured to emit high energy beta particles and high energy photons, and a plurality of NTAC layers integrated with the radioisotope core and the radioisotope sources, wherein the plurality of NTAC layers are configured to receive the beta particles and the photons from the radioisotope core and sources, and by the received beta particles and photons, free up electrons in an avalanche process from deep and intra bands of an atom to output a high density avalanche cell thermal energy through a photo-ionic or thermionic process of the freed up electrons.

Abstract: Systems, methods, and devices of the various embodiments may provide a portable power system for powering small devices that may be small, may be compact, may provide continuous power, and may be lightweight enough for an astronaut to carry. Various embodiments may provide a compact, thermionic-based cell that provides increased energy density and that more efficiently uses a heat source, such as a Pu-238 heat source. Nanometer scale emitters, spaced tightly together, in various embodiments convert a larger amount of heat into usable electricity than in current thermoelectric technology. The emitters of the various embodiments may be formed from various materials, such as copper (Cu), silicon (Si), silicon-germanium (SiGe), and lanthanides. Various embodiments may be added to regenerative thermionic cells with multiple layers to enhance the energy conversion efficiency of the regenerative thermionic cells.

Abstract: Various aspects include electric generators configured to boost electrical output by leveraging electron avalanche generated by a high energy photon radiation source. In various aspects, an electric generator includes a stator and a rotor positioned within the stator, wherein the stator and rotor are configured to generate electric current when the rotor is rotated, and a high energy photon source (e.g., a gamma ray source) positioned and configured to irradiate at least a portion of conductors in the rotor or stator. In some aspects, the stator generates a magnetic field when the electric generator is operating, and the rotor includes armature windings configured to generate electric current when the rotor is rotated. In some aspects, the high energy photon source includes cobalt-60 and/or cesium-137.

Abstract: Systems, methods, and devices of the various embodiments enable a Nuclear Thermionic Avalanche Cell (NTAC) to capture gamma ray photons emitted during a fission process, such as a fission process of Uranium-235 (U-235), and to breed and use a new gamma ray source to increase an overall emission flux of gamma ray photons. Various embodiments combine a fission process with the production of Co-60, thereby boosting the output flux of gamma ray photons for use by a NTAC in generating power. Various embodiments combine a fission process with the production of Co-60, a NTAC generating avalanche cell power, and a thermoelectric generator generating thermoelectric power.

Abstract: Systems, methods, and devices of the various embodiments provide for microfabrication of devices, such as semiconductors, thermoelectric devices, etc. Various embodiments may include a method for fabricating a device, such as a semiconductor (e.g., a silicon (Si)-based complementary metal-oxide-semiconductor (CMOS), etc.), thermoelectric device, etc., using a mask. In some embodiments, the mask may be configured to allow molecules in a deposition plume to pass through one or more holes in the mask. In some embodiments, molecules in a deposition plume may pass around the mask. Various embodiments may provide thermoelectric devices having metallic junctions. Various embodiments may provide thermoelectric devices having metallic junctions rather than junctions formed from semiconductors.

Abstract: A thermionic (TI) power cell includes a heat source, such as a layer of radioactive material that generates heat due to radioactive decay, a layer of electron emitting material disposed on the layer of radioactive material, and a layer of electron collecting material. The layer of electron emitting material is physically separated from the layer of electron collecting material to define a chamber between the layer of electron collecting material and the layer of electron emitting material. The chamber is substantially evacuated to permit electrons to traverse the chamber from the layer of electron emitting material to the layer of electron collecting material. Heat generated over time by the layer of radioactive material causes a substantially constant flow of electrons to be emitted by the layer of electron emitting material to induce an electric current to flow through the layer of electron collecting material when connected to an electrical load.

Abstract: Systems, methods, and devices of the various embodiments may provide a mechanism to enable the growth of a rhombohedral epitaxy at a lower substrate temperature by energizing the atoms in flux, thereby reducing the substrate temperature to a moderate level. In various embodiments, sufficiently energized atoms provide the essential energy needed for the rhombohedral epitaxy process which deforms the original cubic crystalline structure approximately into a rhombohedron by physically aligning the crystal structure of both materials at a lower substrate temperature.

Abstract: A metal junction thermoelectric device includes at least one thermoelectric element. The thermoelectric element has first and second opposite sides, and a first conductor made from a first metal, and a second conductor made from a second metal. The first and second conductors are electrically interconnected in series, and the first and second conductors are arranged to conduct heat in parallel between the first and second sides. The first metal has a first occupancy state, and the second metal has a second occupancy state that is lower than the first occupancy state. A temperature difference between the first and second sides of the thermoelectric element causes a charge potential due to the difference in occupancy states of the first and second metals. The charge potential generates electrical power.

Abstract: A method of forming an epitaxial layer on a substrate such as a sapphire wafer that does not readily absorb thermal radiation. The method includes coating a first side surface of the substrate with an energy-absorbing opaque material. The opaque material forms a thermally absorptive coating on the substrate. The coated substrate may be heated to remove contaminants from the thermally absorptive coating. The coated substrate is positioned in a vacuum deposition chamber and heated by directing radiative energy onto the thermally absorptive coating. An epitaxial layer such as GaN or SiGe is formed on a second side surface of the substrate opposite the thermally absorptive coating.

Abstract: Various embodiments provide Molten Target Sputtering (MTS) methods and devices. The various embodiments may provide increases in the kinetic energy, increases in the energy latency, and/or increases in the flux density of molecules for better crystal formation at low temperature operation. The various embodiment MTS methods and devices may enable the growth of a single crystal Si1-xGex film on a substrate heated to less than about 500° C. The various embodiment MTS methods and devices may provide increases in the kinetic energy, increases in the energy latency, and/or increases in the flux density of molecules without requiring the addition of extra systems.

Abstract: 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 NaBH4 to 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.

Abstract: A new fabrication method for nanovoids-imbedded bismuth telluride (Bi—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—Te material. The final nanovoid structure such as void size, size distribution, void location, etc. can be also controlled under various process conditions.

Abstract: An optical apparatus includes an optical diffraction device configured for diffracting a predetermined wavelength of incident light onto adjacent optical focal points, and a photon detector for detecting a spectral characteristic of the predetermined wavelength. One of the optical focal points is a constructive interference point and the other optical focal point is a destructive interference point. The diffraction device, which may be a micro-zone plate (MZP) of micro-ring gratings or an optical lens, generates a constructive ray point using phase-contrasting of the destructive interference point. The ray point is located between adjacent optical focal points. A method of generating a densely-accumulated ray point includes directing incident light onto the optical diffraction device, diffracting the selected wavelength onto the constructive interference focal point and the destructive interference focal point, and generating the densely-accumulated ray point in a narrow region.

Abstract: “Super-hetero-epitaxial” combinations comprise epitaxial growth of one material on a different material with different crystal structure. Compatible crystal structures may be identified using a “Tri-Unity” system. New bandgap engineering diagrams are provided for each class of combination, based on determination of hybrid lattice constants for the constituent materials in accordance with lattice-matching equations. Using known bandgap figures for previously tested materials, new materials with lattice constants that match desired substrates and have the desired bandgap properties may be formulated by reference to the diagrams and lattice matching equations. In one embodiment, this analysis makes it possible to formulate new super-hetero-epitaxial semiconductor systems, such as systems based on group IV alloys on c-plane LaF3; group IV alloys on c-plane langasite; Group III-V alloys on c-plane langasite; and group II-VI alloys on c-plane sapphire.

Abstract: Metal nanoshells are fabricated by admixing an aqueous solution of metal ions with an aqueous solution of apoferritin protein molecules, followed by admixing an aqueous solution containing an excess of an oxidizing agent for the metal ions. The apoferritin molecules serve as bio-templates for the formation of metal nanoshells, which form on and are bonded to the inside walls of the hollow cores of the individual apoferritin molecules. Control of the number of metal atoms which enter the hollow core of each individual apoferritin molecule provides a hollow metal nonparticle, or nanoshell, instead of a solid spherical metal nanoparticle.