Abstract: One example is a betavoltaic cell that has been fabricated using a semiconductor that includes, but is not limited to, Silicon Carbide (SiC), Silicon (Si), Gallium Arsenide (GaAs), Indium Gallium Arsenide (InGaAs), Gallium Nitide (GaN), Gallium Phosphide (GaP), or Diamond, and uses through wafer via holes or other fabrication techniques to form both positive (+ve) and negative (?ve) contacts on the front and back sides of the cell. In another example, several of these cells with +ve and ?ve contacts on the front and back sides of the cell are arranged vertically and/or horizontally to form customized parallel and/or series combinations that produce a close packed, energy dense betavoltaic composite unit, with increased power outputs relative to a single cell. In another example, tritium or a metal tritide is used as the radioisotope source for the cells.

Abstract: 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.

Abstract: This is a novel SiC betavoltaic device (as an example) which comprises one or more “ultra shallow” P+ N? SiC 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.

Abstract: 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.

Abstract: 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).

Abstract: This is a novel SiC betavoltaic device (as an example) which comprises one or more “ultra shallow” P+N? SiC 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.

Abstract: 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.

Abstract: 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, CCl4, or halogenated hydrocarbons, CHCl3, CH2Cl2, or CH3Cl, 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.

Abstract: This is a novel SiC betavoltaic device (as an example) which comprises one or more “ultra shallow” P+N? SiC 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.

Abstract: 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 CCl4 or halogenated hydrocarbons, CHCl3, CH2Cl2, CH3Cl, 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.