Patents by Inventor Ajay Kumar Kalla

Ajay Kumar Kalla 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).

  • Machine and process for sequential multi-sublayer deposition of copper indium gallium diselenide compound semiconductors
    Patent number: 8465589
    Abstract: A method of manufacture of CIGS photovoltaic cells and modules involves sequential deposition of copper indium gallium diselenide compounds in multiple thin sublayers to form a composite CIGS absorber layer of a desirable thickness greater than the thickness of each sublayer. In an embodiment, the method is adapted to roll-to-roll processing of CIGS PV cells. In an embodiment, the method is adapted to preparation of a CIGS absorber layer having graded composition through the layer. In a particular embodiment, the graded composition is enriched in copper at a base of the layer. In an embodiment, each CIGS sublayer is deposited by co-evaporation of copper, indium, gallium, and selenium which react in-situ to form CIGS.
    Type: Grant
    Filed: February 5, 2010
    Date of Patent: June 18, 2013
    Assignee: Ascent Solar Technologies, Inc.
    Inventors: Prem Nath, Venugopala R. Basava, Ajay Kumar Kalla, Peter Alex Shevchuk, Mohan S. Misra
  • Machine and process for sequential multi-sublayer deposition of copper indium gallium diselenide compound semiconductors
    Patent number: 8021905
    Abstract: A method of manufacture of CIGS photovoltaic cells and modules involves sequential deposition of copper indium gallium diselenide compounds in multiple thin sublayers to form a composite CIGS absorber layer of a desirable thickness greater than the thickness of each sublayer. In an embodiment, the method is adapted to roll-to-roll processing of CIGS PV cells. In an embodiment, the method is adapted to preparation of a CIGS absorber layer having graded composition through the layer. In a particular embodiment, the graded composition is enriched in copper at a base of the layer. In an embodiment, each CIGS sublayer is deposited by co-evaporation of copper, indium, gallium, and selenium which react in-situ to form CIGS.
    Type: Grant
    Filed: April 30, 2010
    Date of Patent: September 20, 2011
    Assignee: Ascent Solar Technologies, Inc.
    Inventors: Prem Nath, Venugopala R. Basava, Ajay Kumar Kalla, Peter Alex Shevchuk, Mohan S. Misra