Medical University of South Carolina

Widetronix, Inc.

Cornell Research Foundation Inc.

Morgan State University

Mvs Chandrashekhar

Michael Spencer

Joshua Letton

Tangali S Sudarshan

Chris D Thomas

Andrew B Greytak

Mathew Kelley

Anusha Balachandran

Venkata Surya N Chava

Goutam Koley

Tawhid Rana

Ifat Jahangir

Christopher Ian Thomas

Travis Williams

Abdulganiyu Ajilore

Sabih U Omar

Gabriel Brown

Shamaita S Shetu

A voltage tunable solar-blind UV detector using a EG/SiC heterojunction based Schottky emitter bipolar phototransistor with EG grown on p-SiC epi-layer using a chemically accelerated selective etching process of Si using TFS precursor.

Voltage tunable solar blindness in TFS grown EG/SiC Schottky contact bipolar phototransistors

The present disclosure is directed to methods for producing a photovoltaic junction that can include coating a bare junction with a composition. In one embodiment, the composition includes a plurality of quantum dots to create a film; exposing the film to a ligand to create a first layer; coating the first layer with the composition to form a film on the first layer; and exposing the film on the first layer to the ligand to create a second layer.

Methods of producing a photovoltaic junction including ligand exchange of quantum dots of a film

Methods for forming a graphene film on a silicon carbide material are provided, along with the resulting coated materials. The method can include: heating the silicon carbide material to a growth temperature (e.g., about 1,000&#xb0; C. to about 2,200&#xb0; C.), and exposing the silicon carbide material to a growth atmosphere comprising a halogen species. The halogen species reacts with the silicon carbide material to remove silicon therefrom. The halogen species can comprise fluorine (e.g., SiF, etc.), chlorine (e.g., SiCl), or a mixture thereof.

Defect engineered high quality multilayer epitaxial graphene growth with thickness controllability

The present disclosure is directed to photovoltaic junctions and methods for producing the same. Embodiments of the disclosure may be incorporated in various devices for applications such as solar cells and light detectors and may demonstrate advantages compared to standard materials used for photovoltaic junctions such as silica. An example embodiment of the disclosure includes a photovoltaic junction, the junction including a light absorbing material, an electron acceptor for shuttling electrons, and a metallic contact. In general, embodiments of the disclosure as disclosed herein include photovoltaic junctions which provide absorption across one or more wavelengths in the range from about 200 nm to about 1000 nm, or from near IR (NIR) to ultra-violet (UV). Generally, these embodiments include a multi-layered light absorbing material that can be formed from quantum dots that are successively deposited on the surface of an electron acceptor (e.g., a semiconductor).

Quantum dot photovoltaic junctions

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

Methods of synthesis and fabrication of a transition metal dichalcogenide (TMD) structures are disclosed. A method can include first patterning a transition metal (TM) on a substrate and placing the substrate in a process chamber. Oxygen can be applied to the transition metal on the substrate and a mixture of highly reactive transition metal oxides can be formed and simultaneously thinned down by sublimation. Finally, a chalcogen can be applied to the substrate and a transition metal dichalcogenide structure can be formed.

Synthesis and fabrication of transition metal dichalcogenide structures

A bi-polar device is provided, along with methods of making the same. The bi-polar device can include a semiconductor substrate doped with a first dopant, a semiconductor layer on the first surface of the semiconductor substrate, and a Schottky barrier layer on the semiconductor layer. The method of forming a bi-polar device can include: forming a semiconductor layer on a first surface of a semiconductor substrate, where the semiconductor substrate comprises a first dopant and where the semiconductor layer comprises a second dopant that has an opposite polarity than the first dopant; and forming a Schottky barrier layer on a first portion of the semiconductor layer while leaving a second portion of the semiconductor layer exposed.

Optically switched graphene/4H-SiC junction bipolar transistor

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

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

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.

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.

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Columbia, SC, United States of America

Mvs Chandrashekhar