Patents by Inventor Krishna M. Koliwad

Krishna M. Koliwad 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).

  • Method of increasing minority carrier lifetime in silicon web or the like
    Patent number: 4401505
    Abstract: A silicon dendrite is grown as a ribbon forming two silicon crystal layers which are separated by an interface layer which contains a large number of defects. Significant increase of minority carrier lifetime with homogeneous distribution at the outer surfaces of the two silicon crystal layers are achieved by processing the web in an atmosphere of a selected gas, e.g. oxygen, nitrogen or an inert gas, for about 30 minutes to several hours at a temperature preferably on the order of 900.degree. C.-1200.degree. C.
    Type: Grant
    Filed: March 31, 1982
    Date of Patent: August 30, 1983
    Assignee: The United States of America as represented by the Administrator National Aeronautics and Space Administration
    Inventors: James K. Liu, Guenter H. Schwuttke, Krishna M. Koliwad
  • Copper doped polycrystalline silicon solar cell
    Patent number: 4249957
    Abstract: Photovoltaic cells having improved performance are fabricated from polycrystalline silicon containing copper segregated at the grain boundaries.
    Type: Grant
    Filed: May 30, 1979
    Date of Patent: February 10, 1981
    Inventors: Alan M. Administrator of the National Aeronautics and Space Administration, with respect to an invention of Lovelace, Krishna M. Koliwad, Taher Daud