Widetronix, Inc.

Cornell Research Foundation Inc.

Cornell University

Medical University of South Carolina

Health Research, Inc.

Ii-vi Incorporated

Morgan State University

Michael Spencer

Mvs Chandrashekhar

Huaqiang Wu

Yuri Makarov

Francis J DiSalvo

Chris D Thomas

Christopher Ian Thomas

Christopher Kemper Ober

Emmanuel P Giannelis

James N Turner

Thomas Radford Sommer

Stephen B Wicker

Farhan Rana

Joshua Letton

Thomas Denis O'Rourke

Phani Konkapaka

Athanasios Bourlinos

M V S Chandrashekhar

Jared Hillel Strait

Travis Williams

Abdulganiyu Ajilore

The localized formation of graphene and diamond like structures on the surface of boron carbide is obtained due to exposure to high intensity laser illumination. The graphitization involves water vapor interacting with the laser illuminated surface of boron carbide and leaving behind excess carbon. The process can be done on the micrometer scale, allowing for a wide range of electronic applications. Raman is a powerful and convenient technique to routinely characterize and distinguish the composition of Boron Carbide (BC), particularly since a wide variation in C content is possible in BC. Graphitization of 1-3 &#x3bc;m icosahedral BC powder is observed at ambient conditions under illumination by a 473 nm (2.62 eV) laser during micro-Raman measurements. The graphitization, with &#x2dc;12 nm grain size, is dependent on the illumination intensity. The process is attributed to the oxidation of BC to BOby water vapor in air, and subsequent evaporation, leaving behind excess carbon. The effectiveness of this process sheds light on amorphization pathways of BC, a critical component of resilient mechanical composites, and also enables a means to thermally produce graphitic contacts on single crystal BC for nanoelectronics.

Laser induced graphitization of boron carbide in air

A plasmon-based optical modulator comprises a substrate, a layer of high reflectivity material disposed over the substrate, a relatively thin dielectric layer disposed over a top major surface of the layer of high reflectivity material and a plurality of graphene strips disposed in parallel across a top major surface of the relatively thin dielectric layer, each graphene strip exhibiting a predetermined width w, with adjacent strips separated by a predetermined spacing s. A first electrical contact is coupled to the plurality of graphene strips and a second electrical contact is coupled to the layer of high reflectivity material, where the values of w, s, and voltage applied between the first and second electrical contacts determines a resonant wavelength of the plasmon-based optical modulator, with changes in the applied voltage changing between absorption and non-absorption of an applied optical input signal.

Thin film plasmonic optical modulator

We introduce a new technology for Manufactureable, High Power Density, High Volume Utilization Nuclear Batteries. Betavoltaic batteries are an excellent choice for battery applications which require long life, high power density, or the ability to operate in harsh environments. In order to optimize the performance of betavoltaic batteries for these applications or any other application, it is desirable to maximize the efficiency of beta particle energy conversion into power, while at the same time increasing the power density of an overall device. Various devices and methods to solve the current industry problems and limitations are presented here.

Nuclear batteries

This is a novel SiC betavoltaic device (as an example) which comprises one or more 'ultra shallow' P+ NSiC junctions and a pillared or planar device surface (as an example). Junctions are deemed 'ultra shallow', since the thin junction layer (which is proximal to the device's radioactive source) is only 300 nm to 5 nm thick (as an example). This is a betavoltaic device, made of ultra-shallow junctions, which allows such penetration of emitted lower energy electrons, thus, reducing or eliminating losses through electron-hole pair recombination at the surface.

Betavoltaic battery with a shallow junction and a method for making same

A sensor system utilizing flexible electronics for on-line real-time high-sensitivity sampling, monitoring, and analysis of a parameter or analyte of interest in a fluid or in or on a solid is provided. The flexible substrate sensor system comprises a plurality of sensors, a flexible substrate, a network, and a connection between the sensors and the network, wherein the network reads out or collects information from the sensors. The network can be onboard, connected by via a physical connection to the sensors and the flexible substrate, or external to the sensors and flexible substrate, connected via a telemetric or wireless connection to the sensors. The flexible substrate sensor system can be deployed in systems that conduct or distribute fluids or solids, such as distribution systems (municipal water systems, oil or gas pipeline systems), industrial systems (production facilities, piping, and storage systems), and large structures (dams, bridges, walkways, buildings).

Flexible substrate sensor system for environmental and infrastructure monitoring

To increase total power in a betavoltaic device, it is desirable to have greater radioisotope material and/or semiconductor surface area, rather than greater radioisotope material volume. An example of this invention is a high power density betavoltaic battery. In one example of this invention, tritium is used as a fuel source. In other examples, radioisotopes, such as Nickel-63, Phosphorus-33 or promethium, may be used. The semiconductor used in this invention may include, but is not limited to, Si, GaAs, GaP, GaN, diamond, and SiC. For example (for purposes of illustration/example, only), tritium will be referenced as an exemplary fuel source, and SiC will be referenced as an exemplary semiconductor material. Other variations and examples are also discussed and given.

High power density betavoltaic battery

A method is described for the growth of high-quality epitaxial silicon carbide (SiC) films and boules, using the Chemical Vapor Deposition (CVD) technique, which comprises the steps of supplying original species SiH4 and CCl4 into a growth chamber, decomposing at elevated temperatures, producing decomposition product SiH2, SiH, Si, CCl3, or CCl2, producing interaction product HCl, CH3Cl, CH4, or SiH2Cl2, etching by one of the byproducts HCl to suppress Si nucleation, providing main species SiCl2 and CH4 at a cooled insert located on sides of a substrate holder and at a shower-head located on top of the substrate holder, in the growth chamber, with proper Si to C atom ratio and Si to Cl atom ratio, to suppress parasitic deposits, and depositing SiC on a substrate at a proper growth substrate temperature (1500 to 1800 centigrade range).

Method for the growth of SiC, by chemical vapor deposition, using precursors in modified cold-wall reactor

This is a novel SiC betavoltaic device (as an example) which comprises one or more 'ultra shallow' P+NSiC junctions and a pillared or planar device surface (as an example). Junctions are deemed 'ultra shallow', since the thin junction layer (which is proximal to the device's radioactive source) is only 300 nm to 5 nm thick (as an example). In one example, tritium is used as a fuel source. In other embodiments, radioisotopes (such as Nickel-63, promethium or phosphorus-33) may be used. Low energy beta sources, such as tritium, emit low energy beta-electrons that penetrate very shallow distances (as shallow as 5 nm) in semiconductors, including SiC, and can result in electron-hole pair creation near the surface of a semiconductor device rather than pair creation in a device's depletion region. By contrast, as a high energy electron penetrates a semiconductor device surface, such as a diode surface, it produces electron hole-pairs that can be collected at (by drift) and near (by diffusion) the depletion region of the device. This is a betavoltaic device, made of ultra-shallow junctions, which allows such penetration of emitted lower energy electrons, thus, reducing or eliminating losses through electron-hole pair recombination at the surface.

We introduce a new technology for Manufacturable, High Power Density, High Volume Utilization Nuclear Batteries. Betavoltaic batteries are an excellent choice for battery applications which require long life, high power density, or the ability to operate in harsh environments. In order to optimize the performance of betavoltaic batteries for these applications or any other application, it is desirable to maximize the efficiency of beta particle energy conversion into power, while at the same time increasing the power density of an overall device. The small (submicron) thickness of the active volume of both the isotope layer and the semiconductor device is due to the short absorption length of beta electrons. The absorption length determines the self absorption of the beta particles in the radioisotope layer as well as the range, or travel distance, of the betas in the semiconductor converter which is typically a semiconductor device comprising at least one PN junction. Various devices and methods to solve the current industry problems and limitations are presented here.

A novel approach for the growth of high-quality on-axis epitaxial silicon carbide (SiC) films and boules, using the Chemical Vapor Deposition (CVD) technique, is described here. The method includes a method of substrate preparation, which allows for the growth of 'on-axis' SiC films, plus an approach giving the opportunity to grow silicon carbide on singular (a small-angle miscut) substrates, using halogenated carbon-containing precursors (carbon tetrachloride, CCl, or halogenated hydrocarbons, CHCl, CHCl, or CHCl, or similar compounds or chemicals), or introducing other chlorine-containing species, in the gas phase, in the growth chamber. At gas mixtures greater than the critical amount, small clusters of SiC are etched, before they can become stable nuclei. The presence of chlorine and the formation of gas species allow an increased removal rate of these nuclei, in contrast to the growth without the presence of chlorine. Or, alternatively, the novel precursors introduced in the growth system reduce the effective supersaturation ratio of the Si species in the growth layer. The reduction of the supersaturation ratio reduces or eliminates the 2D (and 3C&#x2014;SiC) nucleation which would occur due to the large terrace widths present on the on-axis wafers. This allows the growth of Silicon Carbide epitaxial layers on SiC substrates or composite substrates with monocrystalline layers. This can also be applied to the other semiconductors, chemicals, compounds, materials, growth methods, or devices.

Method, system, and apparatus for the growth of on-axis SiC and similar semiconductor materials

High aspect ratio micromachined structures in semiconductors are used to improve power density in Betavoltaic cells by providing large surface areas in a small volume. A radioactive beta-emitting material may be placed within gaps between the structures to provide fuel for a cell. The pillars may be formed of SiC. In one embodiment, SiC pillars are formed of n-type SiC. P type dopant, such as boron is obtained by annealing a borosilicate glass boron source formed on the SiC. The glass is then removed. In further embodiments, a dopant may be implanted, coated by glass, and then annealed. The doping results in shallow planar junctions in SiC.

Betavoltaic cell

An approach for the growth of high-quality epitaxial silicon carbide (SiC) films and boules, using the Chemical Vapor Deposition (CVD) technique is described here. The method comprises modifications in the design of the typical cold-wall CVD reactors, providing a better temperature uniformity in the reactor bulk and a low temperature gradient in the vicinity of the substrate, and an approach to increase the silicon carbide growth rate and to improve the quality of the growing layers, using halogenated carbon-containing precursors (carbon tetrachloride CClor halogenated hydrocarbons, CHCl, CHCl, CHCl, etc.), or introducing other chlorine-containing species in the gas phase in the growth chamber. The etching effect, proper ranges, and high temperature growth are also examined.

Method, system, and apparatus for the growth of SiC and related or similar material, by chemical vapor deposition, using precursors in modified cold-wall reactor

GaN is grown by creating a Ga vapor from a powder, and using an inert purge gas from a source to transport the vapor to a growth site where the GaN growth takes place. In one embodiment, the inert gas is N, and the powder source is GaN powder that is loaded into source chambers. The GaN powder is congruently evaporated into Ga and Nvapors at temperatures between approximately 1000 and 1200&#xb0; C. The formation of Ga liquid in the powder is suppressed by the purging of an inert gas through the powder. The poser may also be isolated from a nitride containing gas provided at the growth cite. In one embodiment, the inert gas is flowed through the powder.

GaN bulk growth by Ga vapor transport

The invention provides a composition that is a dispersion made from a Group III nitride, a solvent system, and a dispersant. The dispersion can be used to prepare Group III nitride thin films on a wide range of substrates, for example, glass, silicon, silicon dioxide, silicon nitride, silicon carbide, aluminum nitride, sapphire, and organic polymers. The particle size of the Group III nitride used for producing the thin films can be controlled by adjusting centrifugation of the dispersion and selecting a desired layer of supernatant. The dispersant can be removed from the thin films by calcination. The Group III nitride can contain a dopant. Doped Group III nitride thin films can emit visible light upon irradiation. Green, red, and yellow light emissions result from irradiating erbium-, europium-, and cerium-doped gallium nitride, respectively.

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Ithaca, NY, United States of America

Michael Spencer