Patents by Inventor Allen M. Barnett
Allen M. Barnett has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 5356509Abstract: A method for growing a compound semiconductor, such as GaAs or InP, on a non-lattice matched substrate, such as Si, utilizes close-spaced vapor transport to deposit nucleation enhancing interlayer and liquid phase epitaxy to form the compound semiconductor. When used in conjunction with a growth mask, the method is also adapted to selective area epitaxy.Type: GrantFiled: October 16, 1992Date of Patent: October 18, 1994Assignee: AstroPower, Inc.Inventors: Nancy Terranova, Allen M. Barnett
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Patent number: 5336335Abstract: The invention relates to techniques for manufacturing columnar-grained polycrystalline sheets which have particular utility as substrates or wafers for solar cells. The sheet is made by applying granular silicon to a setter material which supports the granular material. The setter material and granular silicon are subjected to a thermal profile all of which promote columnar growth by melting the silicon from the top downwardly. The thermal profile sequentially creates a melt region at the top of the granular silicon and then a growth region where both liquid and a growing polycrystalline sheet layer coexist. An annealing region is created where the temperature of the grown polycrystalline silicon sheet layer is controllably reduced to effect stress relief.Type: GrantFiled: October 9, 1992Date of Patent: August 9, 1994Assignee: AstroPower, Inc.Inventors: Robert B. Hall, Allen M. Barnett, Jacob E. Brown, Joseph C. Checchi, David H. Ford, Christopher L. Kendall, William P. Mulligan, James A. Rand, Todd R. Ruffins
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Patent number: 5266125Abstract: A plurality of thin polycrystalline silicon solar cells formed on a ceramic substrate and which are electrically series connected to form a monolithically interconnected submodule. Adjacent solar cells are electrically separated by a vertical trench and electrically connected by interconnects located below the light receiving surface of each solar cell. The submodules are provided with external electrical contacts for electrically connecting into a photovoltaic module assembly.Type: GrantFiled: May 12, 1992Date of Patent: November 30, 1993Assignee: AstroPower, Inc.Inventors: James A. Rand, Allen M. Barnett, Robert B. Hall
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Patent number: 5144377Abstract: A high-speed heterojunction light-emitting diode is formed by providing a dielectric layer on a heavily doped semiconductor substrate having short minority carrier lifetime. A semiconductor layer of opposite conductivity to the substrate is epitaxially grown through vias in the dielectric layer. This results in a junction area equal to the useful light-emitting area. An electrical contact is formed on the laterally overgrown area of the epitaxially grown material. The diode manufacture is compatible with planar processing techniques commonly used in integrated circuit manufacture.Type: GrantFiled: April 4, 1991Date of Patent: September 1, 1992Assignee: University of DelawareInventors: Allen M. Barnett, John B. Berryhill
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Patent number: 5057163Abstract: A thin-film photovoltaic solar cell features a thin polycrystalline silicon active semiconductor formed over a conductive ceramic substrate. Between the substrate and the adjacent active semiconductor layer is a barrier layer which provides for reflection of light, minimizes back surface recombination and prevents contamination of the active semiconductor.Type: GrantFiled: May 4, 1988Date of Patent: October 15, 1991Assignee: AstroPower, Inc.Inventors: Allen M. Barnett, Robert B. Hall, James A. Rand, David H. Ford
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Patent number: 4876210Abstract: The effects of excessive lattice mismatch in solution grown heterostructures are reduced by incorporating a lattice graded interface layer between the substrate and the heteroepitaxial layer. The effects of lattice mismatch are also reduced by reducing the contact area with a selective growth mask which controls where growth initiates on the substrate. The effect of mismatched solubility is reduced by double saturation of the solvent and selective supersaturation of the solvent.Type: GrantFiled: March 4, 1988Date of Patent: October 24, 1989Assignee: The University of DelawareInventors: Allen M. Barnett, John C. Zolper
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Patent number: 4818337Abstract: High efficiency, thin active-layer silicon solar cells and a process for their fabrications have been provided. The cells are characterized by a capability of employing a low-cost, metallurgical grade silicon for the substrate. The substrate has a silicon dioxide barrier coating with electrical conductivity to the active semiconductor layers provided by a multiplicity of fine holes through the oxide. The holes have silicon therein to afford electrical continuity between the active layers and the silicon of the substrate. The process comprises in situ formation of silicon dioxide on the silicon, formation of the holes in the oxide by photolithography, and etching enabling nucleation and growth of silicon in the holes by epitaxy.Type: GrantFiled: April 11, 1986Date of Patent: April 4, 1989Assignee: University of DelawareInventors: Allen M. Barnett, Michael G. Mauk
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Patent number: 4781766Abstract: A thin-film solar cell is made up of semiconductor layers formed on an aluminum silicon eutectic alloy substrate. The substrate includes an aluminum oxide insulator containing electrically conducting silicon nucleation sites which is interposed between the electrical contact of the substrate and the adjacent semiconductor. Grain boundaries and voids terminate on the insulator. The solar cell is fabricated by oxidizing the aluminum-silicon substrate to form a layer of aluminum oxide with unactivated silicon site material dispersed therein and activating the silicon nucleation sites during growth of the semiconductor layers.Type: GrantFiled: May 29, 1987Date of Patent: November 1, 1988Assignee: Astrosystems, Inc.Inventors: Allen M. Barnett, Robert B. Hall, Jeff W. Edington, Alexander P. Davidson, William A. Tiller
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Patent number: 4778478Abstract: Solar cell quality semiconductors are grown using a constant temperature sliding boat liquid phase process in a continuous or semi-continuous mode. The growth is driven by applying a temperature gradient or other gradient across the melt, with the substrate at a cooler temperature, after thermal equilibrium is obtained between the solution and the substrate. Growth occurs from the bottom of the solution to prevent contamination of the growth layers by extraneous particles in the solution.Type: GrantFiled: December 20, 1985Date of Patent: October 18, 1988Assignee: University of DelawareInventor: Allen M. Barnett
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Patent number: 4772564Abstract: A thin-film solar cell on a substrate is fabricated by selectively introducing nucleation sites into the insulator layer which is formed on the substrate material, and activating the nucleation sites during growth of the semiconductor layers. The solar cell is made up of semiconductor layers formed on a substrate. The substrate includes an insulator containing electrically conducting nucleation sites which is interposed between the electrical contact of the substrate and the adjacent semiconductor. The insulator can also be optically transparent. Grain boundaries and voids terminate on the insulator.Type: GrantFiled: May 13, 1987Date of Patent: September 20, 1988Assignee: Astrosystems, Inc.Inventors: Allen M. Barnett, Robert B. Hall
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Patent number: 4677250Abstract: A thin-film solar cell is made up of semiconductor layers formed on a substrate. The substrate includes an insulator containing electrically conducting nucleation sites which is interposed between the electrical contact of the substrate and the adjacent semiconductor. The insulator can also be optically transparent. Grain boundaries and voids terminate on the insulator. The solar cell is fabricated by selectively introducing nucleation sites into the insulator layer which is formed on the substrate material, and activating the nucleation sites during growth of the semiconductor layers.Type: GrantFiled: October 30, 1985Date of Patent: June 30, 1987Assignee: Astrosystems, Inc.Inventors: Allen M. Barnett, Robert B. Hall
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Patent number: 4582952Abstract: An improved tandem solar cell includes a gallium arsenide phosphide top solar cell and silicon bottom solar cell. The gallium arsenide phosphide solar cell is fabricated on a transparent gallium phosphide substrate and either placed in series with the silicon solar cell for a two terminal device or wired separately for a four terminal device. The top solar cell should have an energy gap between 1.77 and 2.09 eV for optimum energy conversion efficiency. A compositionally graded transition layer between the gallium phosphide substrate and the active semiconductor layers reduces dislocations in the active region. A gallium phosphide cap layer over the gallium arsenide phosphide solar cell reduces surface recombination losses.Type: GrantFiled: April 30, 1984Date of Patent: April 15, 1986Assignee: Astrosystems, Inc.Inventors: James B. McNeely, Allen M. Barnett
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Patent number: 4571448Abstract: A thin film photovoltaic solar cell having an opaque electrical contact which consists of a low-cost substrate, such as a metal alloy or a metallurgical grade crystalline silicon and a barrier layer which is optically reflective, a first semiconductor layer, a second semiconductor layer, a transparent electrical contact and an encapsulant.Type: GrantFiled: November 16, 1981Date of Patent: February 18, 1986Assignee: University of DelawareInventor: Allen M. Barnett
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Patent number: 4544799Abstract: Passivated gallium arsenide solar photovoltaic cells with high resistance to moisture and oxygen are provided by means of a gallium arsenide phosphide window graded through its thickness from arsenic rich to phosphorus rich.Type: GrantFiled: April 30, 1984Date of Patent: October 1, 1985Assignee: University of DelawareInventor: Allen M. Barnett
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Patent number: 4477688Abstract: A photovoltaic cell having a zinc phosphide absorber. The zinc phosphide can be a single or multiple crystal slice or a thin polycrystalline film. The cell can be a Schottky barrier, heterojunction or homojunction device. Methods for synthesizing and crystallizing zinc phosphide are disclosed as well as a method for forming thin films.Type: GrantFiled: September 22, 1978Date of Patent: October 16, 1984Assignee: The University of DelawareInventors: Allen M. Barnett, Anthony W. Catalano, Vikram L. Dalal, James V. Masi, John D. Meakin, Robert B. Hall
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Patent number: 4318938Abstract: A technique for manufacturing durable, reliable solar cells by a continuous process suitable for large-scale manufacture involves, in substance, providing a reel of thin metal foil substrate and forming on the substrate a series of layers operative to form a photovoltaic junction, short prevention blocking layers, contacts and integral encapsulation. The foil substrate is processed as a continuous reel substantially until final testing at which point, if desired, it can be cut into individual cells for deployment. In comparison with a batch process, the continuous technique can reduce manufacturing cost by as much as a factor of two.Type: GrantFiled: May 29, 1979Date of Patent: March 9, 1982Assignee: The University of DelawareInventors: Allen M. Barnett, Bill N. Baron, James V. Masi, T. W. Fraser Russell
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Patent number: 4251286Abstract: Electrical path failures in thin film photovoltaic cells are avoided by disposing at least one blocking layer in the cell to prevent undesired electrical contact which might otherwise occur between the transparent and opaque electrical contacts as well as between one of the contacts and the semiconductor which is remote from it.Type: GrantFiled: September 18, 1979Date of Patent: February 17, 1981Assignee: The University of DelawareInventor: Allen M. Barnett
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Patent number: 4239553Abstract: A solar cell having a copper-bearing absorber is provided with a composite transparent encapsulating layer specifically designed to prevent oxidation of the copper sulfide. In a preferred embodiment, the absorber is a layer of copper sulfide and the composite layer comprises a thin layer of copper oxide formed on the copper sulfide and a layer of encapsulating glass formed on the oxide. It is anticipated that such devices, when exposed to normal operating conditions of various terrestrial applications, can be maintained at energy conversion efficiencies greater than one-half the original conversion efficiency for periods as long as thirty years.Type: GrantFiled: May 29, 1979Date of Patent: December 16, 1980Assignee: University of DelawareInventors: Allen M. Barnett, James V. Masi, Robert B. Hall