Patents by Inventor John C. Evans, Jr.

John C. Evans, Jr. 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).

  • Patent number: 4360701
    Abstract: A heat transparent high intensity solar cell has improved efficiency.A surface of each solar cell (10,16,22) has a plurality of grooves (12,14,18,20,24). Each groove has a vertical face (26,30) and a slanted face (28,32) that is covered by a reflecting metal (34,36).Light rays (38,40) are reflected from the slanted face through the vertical face where they traverse a photovoltaic junction (60). As the light rays travel to the slanted face of an adjacent groove, they again traverse the junction. The underside of the reflecting coating directs the light rays toward the opposite surface of solar cell as they traverse the junction again. When the light rays travel through the solar cell and reach the saw toothed grooves on the under side, the process of reflection and repeatedly traversing the junction again takes place. The light rays ultimately emerge from the solar cell as shown in FIG. 4.
    Type: Grant
    Filed: May 15, 1981
    Date of Patent: November 23, 1982
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventor: John C. Evans, Jr.
  • Patent number: 4341918
    Abstract: A high voltage multijunction solar cell is provided wherein a plurality of discrete voltage generating regions or unit cells are formed in a single generally planar semiconductor body (12). The unit cells comprise a doped regions (20, 22) of opposite conductivity type separated by a gap or undiffused region (24). Metal contacts (26) connect adjacent cells together in series so that the output voltages of the individual cells are additive. In some embodiments, doped field regions (14) separated by gap (16) overlie the unit cells but the cells may be formed in both faces of the wafer (FIG. 2).
    Type: Grant
    Filed: December 24, 1980
    Date of Patent: July 27, 1982
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventors: John C. Evans, Jr., An-Ti Chai, Chandra P. Goradia
  • Patent number: 4335503
    Abstract: A method is provided for making a high voltage multijunction solar cell which comprises a plurality of discrete voltage generating regions, or unit cells, which are formed in a single semiconductor wafer (10) and are connected together so that the voltages of the individual cells are additive. The unit cells comprise doped regions of opposite conductivity types (30, 32) separated by a gap. The method includes forming V-shaped grooves (16) in the wafer and thereafter orienting the wafer so that ions of one conductivity type can be implanted in one face (e.g., 16a) of the groove while the other face (e.g., 16b) is shielded. A metallization layer (22) is applied and selectively etched away to provide connections between the unit cells.
    Type: Grant
    Filed: December 24, 1980
    Date of Patent: June 22, 1982
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventors: John C. Evans, Jr., An-Ti Chai, Chandra P. Goradia
  • Patent number: 4217633
    Abstract: A monolithie multijunction solar cell is modified by fabricating an integrated circuit inverter on the back of the cell to produce a device capable of generating an alternating current output. In another embodiment, integrated circuit power conditioning electronics is incorporated in a module containing a solar cell power supply.
    Type: Grant
    Filed: August 10, 1979
    Date of Patent: August 12, 1980
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventor: John C. Evans, Jr.
  • Patent number: 4135290
    Abstract: A heterojunction or Schottky barrier photovoltaic device comprising a conductive base metal layer compatible with and coating predominately the exposed surface of the p-type substrate of the device such that a back surface field region is formed at the interface between the device and the base metal layer, a transparent, conductive mixed metal oxide layer in integral contact with the n-type layer of the heterojunction or Schottky barrier device having a metal alloy grid network of the same metal elements of the oxide constituents of the mixed metal oxide layer embedded in the mixed metal oxide layer, an insulating layer which prevents electrical contact between the conductive metal base layer and the transparent, conductive metal oxide layer, and a metal contact means covering the insulating layer and in intimate contact with the metal grid network embedded in the transparent, conductive oxide layer for conducting electrons generated by the photovoltaic process from the device.
    Type: Grant
    Filed: December 23, 1977
    Date of Patent: January 23, 1979
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventor: John C. Evans, Jr.
  • Patent number: 4122214
    Abstract: A transparent, conductive collector layer containing conductive metal channels is formed as a layer on a photovoltaic substrate by coating a photovoltaic substract with a conductive mixed metal layer; attaching a heat sink having portions protruding from one of its surfaces which define a continuous pattern in combination with recessed regions among said protruding portions to said substrate such that said protruding portions of said heat sink are in contact with the conductive layer of said substrate; andHeating said substrate while simultaneously oxidizing the portions of the conductive layer exposed to a gaseous oxidizing substance forced into said recessed regions of said heat sink, thereby creating a transparent metal oxide layer on said substrate containing a continuous pattern of highly conductive metal channels in said layer.
    Type: Grant
    Filed: October 21, 1977
    Date of Patent: October 24, 1978
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventor: John C. Evans, Jr.
  • Patent number: 4104091
    Abstract: Diffusants are applied onto semiconductor solar cell substrates using screen printing techniques. The method is applicable to square and rectangular cells and can be used to apply dopants of opposite types to the front and back of the substrate. Then, simultaneous diffusion of both dopants can be performed with a single furnace pass.
    Type: Grant
    Filed: May 20, 1977
    Date of Patent: August 1, 1978
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventors: John C. Evans, Jr., Henry W. Brandhorst, Jr., George A. Mazaris, Larry R. Scudder
  • Patent number: 4104084
    Abstract: A heterojunction or Schottky barrier photovoltaic device comprising a conductive base metal layer compatible with and coating predominately the exposed surface of the p-type substrate of the device such that a back surface field region is formed at the interface between the device and the base metal layer, a transparent, conductive mixed metal oxide layer in integral contact with the n-type layer of the heterojunction or Schottky barrier device having a metal alloy grid network of the same metal elements of the oxide constituents of the mixed metal oxide layer embedded in the mixed metal oxide layer, an insulating layer which prevents electrical contact between the conductive metal base layer and the transparent, conductive metal oxide layer, and a metal contact means convering the insulating layer and in intimate contact with the metal grid network embedded in the transparent, conductive oxide layer for conducting electrons generated by the photovoltaic process from the device.
    Type: Grant
    Filed: June 6, 1977
    Date of Patent: August 1, 1978
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventor: John C. Evans, Jr.
  • Patent number: 4084985
    Abstract: A solar cell panel is fabricated by photoetching a pattern of collector grid systems with appropriate interconnections and bus bar tabs into a glass or plastic sheet. These regions are then filled with a first, thin conductive metal film followed by a layer of a mixed metal oxide, such as InAsO.sub.x or InSnO.sub.x. The multiplicity of solar cells are bonded between the protective sheet at the sites of the collector grid systems and a back electrode substrate by conductive metal filled epoxy to complete the fabrication of an integrated solar panel.
    Type: Grant
    Filed: April 25, 1977
    Date of Patent: April 18, 1978
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventor: John C. Evans, Jr.
  • Patent number: 4082569
    Abstract: A transparent, conductive collector layer containing conductive metal channels is formed as a layer on a photovoltaic substrate by coating a photovoltaic substrate with a conductive mixed metal layer; attaching a heat sink having portions protruding from one of its surfaces which define a continuous pattern in combination with recessed regions among said protruding portions to said substrate such that said protruding portions of said heat sink are in contact with the conductive layer of said substrate; andHeating said substrate while simultaneously oxidizing the portions of the conductive layer exposed to a gaseous oxidizing substance forced into said recessed regions of said heat sink, thereby creating a transparent metal oxide layer on said substrate containing a continuous pattern of highly conductive metal channels in said layer.
    Type: Grant
    Filed: February 22, 1977
    Date of Patent: April 4, 1978
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventor: John C. Evans, Jr.