Abstract: In one preferred embodiment, a semiconductor diode includes a first layer formed with a p-type semiconductor, a second layer formed with an n-type semiconductor, and a third active depletion layer contained between the first and second layers. The third layer is formed with a radioisotope of the p-type and n-type semiconductors (preferably Si 32) such that initial emission of beta particles begins in the active depletion region and substantially all of the emitted beta particles are contained within the first, second and third layers during operation. The p-type and n-type layers each have sufficient depth to contain substantially all of beta particles emitted from the depletion layer. The depth of each of the p-type and n-type layers is substantially equal to or greater than the maximum beta emission depth of the radioisotope.

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: In one preferred embodiment, a semiconductor diode includes a first layer formed with a p-type semiconductor, a second layer formed with an n-type semiconductor, and a third active depletion layer contained between the first and second layers. The third layer is formed with a radioisotope of the p-type and n-type semiconductors (preferably Si 32) such that initial emission of beta particles begins in the active depletion region and substantially all of the emitted beta particles are contained within the first, second and third layers during operation. The p-type and n-type layers each have sufficient depth to contain substantially all of beta particles emitted from the depletion layer. The depth of each of the p-type and n-type layers is substantially equal to or greater than the maximum beta emission depth of the radioisotope.

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: To grow a gallium nitride crystal, a seed-crystal substrate is first immersed in a melt mixture containing gallium and sodium. Then, a gallium nitride crystal is grown on the seed-crystal substrate under heating the melt mixture in a pressurized atmosphere containing nitrogen gas and not containing oxygen. At this time, the gallium nitride crystal is grown on the seed-crystal substrate under a first stirring condition of stirring the melt mixture, the first stirring condition being set for providing a rough growth surface, and the gallium nitride crystal is subsequently grown on the seed-crystal substrate under a second stirring condition of stirring the melt mixture, the second stirring condition being set for providing a smooth growth surface.

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: 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.