Patents Assigned to Davis, Joseph & Negley
  • Patent number: 7297868
    Abstract: A photovoltaic cell exhibiting an overall conversion efficiency of at least 9.0% is prepared from a copper-indium-gallium-diselenide thin film. The thin film is prepared by simultaneously electroplating copper, indium, gallium, and selenium onto a substrate using a buffered electro-deposition bath. The electrodeposition is followed by adding indium to adjust the final stoichiometry of the thin film.
    Type: Grant
    Filed: July 25, 2003
    Date of Patent: November 20, 2007
    Assignee: Davis, Joseph & Negley
    Inventor: Raghu Nath Bhattacharya
  • Publication number: 20020189665
    Abstract: A photovoltaic cell exhibiting an overall conversion efficiency of at least 9.0% is prepared from a copper-indium-gallium-diselenide thin film. The thin film is prepared by simultaneously electroplating copper, indium, gallium, and selenium onto a substrate using a buffered electro-deposition bath. The electrodeposition is followed by adding indium to adjust the final stoichiometry of the thin film.
    Type: Application
    Filed: April 10, 2001
    Publication date: December 19, 2002
    Applicant: DAVIS, JOSEPH & NEGLEY
    Inventor: Raghu Nath Bhattacharya
  • Patent number: 5871630
    Abstract: A photovoltaic cell exhibiting an overall conversion efficiency of 13.6% is prepared from a copper-indium-gallium-diselenide precursor thin film. The film is fabricated by first simultaneously electrodepositing copper, indium, gallium, and selenium onto a glass/molybdenum substrate (12/14). The electrodeposition voltage is a high frequency AC voltage superimposed upon a DC voltage to improve the morphology and growth rate of the film. The electrodeposition is followed by physical vapor deposition to adjust the final stoichiometry of the thin film to approximately Cu(In.sub.1-n Ga.sub.x)Se.sub.2, with the ratio of Ga/(In+Ga) being approximately 0.39.
    Type: Grant
    Filed: June 5, 1997
    Date of Patent: February 16, 1999
    Assignee: Davis, Joseph & Negley
    Inventors: Raghu N. Bhattacharya, Falah S. Hasoon, Holm Wiesner, James Keane, Rommel Noufi, Kannan Ramanathan
  • Patent number: 5804054
    Abstract: High quality thin films of copper-indium-gallium-diselenide useful in the production of solar cells are prepared by electrodepositing at least one of the constituent metals onto a glass/Mo substrate, followed by physical vapor deposition of copper and selenium or indium and selenium to adjust the final stoichiometry of the thin film to approximately Cu(In,Ga)Se.sub.2. Using an AC voltage of 1-100 KHz in combination with a DC voltage for electrodeposition improves the morphology and growth rate of the deposited thin film. An electrodeposition solution comprising at least in part an organic solvent may be used in conjunction with an increased cathodic potential to increase the gallium content of the electrodeposited thin film.
    Type: Grant
    Filed: November 26, 1997
    Date of Patent: September 8, 1998
    Assignee: Davis, Joseph & Negley
    Inventors: Raghu N. Bhattacharya, Miguel A. Contreras, James Keane, Andrew L. Tennant, John R. Tuttle, Kannan Ramanathan, Rommel Noufi
  • Patent number: 5730852
    Abstract: High quality thin films of copper-indium-gallium-diselenide useful in the production of solar cells are prepared by electrodepositing at least one of the constituent metals onto a glass/Mo substrate, followed by physical vapor deposition of copper and selenium or indium and selenium to adjust the final stoichiometry of the thin film to approximately Cu(In,Ga)Se.sub.2. Using an AC voltage of 1-100 KHz in combination with a DC voltage for electrodeposition improves the morphology and growth rate of the deposited thin film. An electrodeposition solution comprising at least in part an organic solvent may be used in conjunction with an increased cathodic potential to increase the gallium content of the electrodeposited thin film.
    Type: Grant
    Filed: December 12, 1995
    Date of Patent: March 24, 1998
    Assignee: Davis, Joseph & Negley
    Inventors: Raghu N. Bhattacharya, Miguel A. Contreras, James Keane, Andrew L. Tennant, John R. Tuttle, Kannan Ramanathan, Rommel Noufi
  • Patent number: 5550104
    Abstract: A method for making superconducting ceramic precursor films by electrodeposition. In the electrodeposition step, superconducting precursor metal ions are electrodeposited onto a working electrode by applying a combined direct current voltage upon which is superimposed an alternating current having a frequency of between about 5 to 100 KHz. The resulting electrodeposited film is particularly well suited for further oxidation/annealing to form a superconducting ceramic.
    Type: Grant
    Filed: September 9, 1994
    Date of Patent: August 27, 1996
    Assignee: Davis, Joseph & Negley
    Inventor: Raghu N. Bhattacharya