Betavoltaic cell
AssigneeCornell Research Foundation, Inc.
InventorsM V S Chandrashekhar, Christopher Ian Thomas, Michael G. Spencer
Life of this patent
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Abstract
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.
Claims22
A Betavoltaic cell comprising:
- a semiconductor substrate;
- p-n junctions formed of semiconductor;
- and
- electrical contacts coupled to the p-n junctions, wherein the contacts are adapted to minimize beta radiation backscatter losses.
A Betavoltaic cell comprising:
- a semiconductor substrate;
- p-n junctions formed from semiconductor;
- cathode or anode contacts coupled to the p-n junctions wherein contact areas are adapted to minimize beta radiation backscatter losses;
- an anode or cathode contact formed on a back side of the substrate;
- and
- a beta radiation fuel.
A Betavoltaic cell comprising:
- a semiconductor substrate;
- p-n junctions formed of semiconductor,
- a void proximal to the p-n junctions;
- cathode or anode contacts coupled to the p-n junctions, wherein the contacts have an area adapted to minimize beta radiation backscatter losses;
- an anode or cathode contact formed on a back side of the substrate;
- and
- a cap formed of semiconductor.
A Betavoltaic cell comprising:
- a semiconductor substrate having a passivated surface;
- p-n junctions formed of semiconductor supported by the semiconductor substrate, wherein an upper layer of the junctions comprise a passivated surface;
- a void proximal to the p-n junctions adapted to hold beta radiation particles;
- first contacts coupled to the p-n junctions, wherein the first contacts occupy less than about 1% of the area of the p-n junctions to minimize beta radiation backscatter losses;
- a second contact formed on a back side of the substrate;
- and
- a cap formed of semiconductor positioned to cover the void.
Dependencies are inferred from the claim text.