Patents by Inventor Kannan Ramanathan
Kannan Ramanathan 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: 9768015Abstract: Methods for forming CIGS films are provided. According to an aspect of the invention, a method of forming a CIGS film includes a precursor step, which includes simultaneously evaporating Cu, In, Ga, Se, and Sb onto a substrate. The Se is incident on the substrate at a rate of at least 20 ?/s. The method also includes a selenization step, which includes evaporating Se over the substrate after the precursor step.Type: GrantFiled: June 1, 2016Date of Patent: September 19, 2017Assignee: Alliance for Sustainable Energy, LLCInventors: Lorelle Mansfield, Kannan Ramanathan
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Publication number: 20160365471Abstract: Methods for forming CIGS films are provided. According to an aspect of the invention, a method of forming a CIGS film includes a precursor step, which includes simultaneously evaporating Cu, In, Ga, Se, and Sb onto a substrate. The Se is incident on the substrate at a rate of at least 20 ?/s. The method also includes a selenization step, which includes evaporating Se over the substrate after the precursor step.Type: ApplicationFiled: June 1, 2016Publication date: December 15, 2016Inventors: Lorelle MANSFIELD, Kannan RAMANATHAN
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Patent number: 8628997Abstract: A method for fabricating a thin film photovoltaic device is provided. The method includes providing a substrate comprising a thin film photovoltaic absorber which has a surface including copper, indium, gallium, selenium, and sulfur. The method further includes subjecting the surface to a material containing at least a zinc species substantially free of any cadmium. The surface is heated to cause formation of a zinc doped material. The zinc doped material is free from cadmium. Furthermore the method includes forming a zinc oxide material overlying the zinc doped material and forming a transparent conductive material overlying the zinc oxide material.Type: GrantFiled: September 19, 2011Date of Patent: January 14, 2014Assignee: Stion CorporationInventors: Kannan Ramanathan, Robert D. Wieting
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Publication number: 20120240989Abstract: A method for fabricating a thin film photovoltaic device is provided. The method includes providing a substrate comprising a thin film photovoltaic absorber which has a surface including copper, indium, gallium, selenium, and sulfur. The method further includes subjecting the surface to a material containing at least a zinc species substantially free of any cadmium. The surface is heated to cause formation of a zinc doped material. The zinc doped material is free from cadmium. Furthermore the method includes forming a zinc oxide material overlying the zinc doped material and forming a transparent conductive material overlying the zinc oxide material.Type: ApplicationFiled: September 19, 2011Publication date: September 27, 2012Applicant: Stion CorporationInventors: Kannan Ramanathan, Robert D. Wieting
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Publication number: 20110259395Abstract: A high efficiency thin-film photovoltaic module is formed on a substrate. The photovoltaic module includes a plurality of stripe shaped photovoltaic cells electrically coupled to each other and physically disposed in parallel to the length one next to another across the width. Each cell includes a barrier material overlying the surface and a first electrode overlying the barrier material. Each cell further includes an absorber formed overlying the first electrode. The absorber includes a copper gallium indium diselenide compound material characterized by an energy band-gap of about 1 eV to 1.1 eV. Each cell additionally includes a buffer material overlying the absorber and a bi-layer zinc oxide material comprising a high resistivity transparent layer overlying the buffer material and a low resistivity transparent layer overlying the high resistivity transparent layer.Type: ApplicationFiled: April 13, 2011Publication date: October 27, 2011Applicant: Stion CorporationInventors: Robert D. Wieting, Rajiv Pethe, Kannan Ramanathan, May Shao, Ashish Tandon
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Publication number: 20110108087Abstract: One photovoltaic module includes a plurality of photovoltaic cells and at least one device selected from a sensor, a data storage device and an indicator. Another photovoltaic module includes a plurality of photovoltaic cells and a flexible circuit configured to act as an antenna for electromagnetic radiation. Methods of using such photovoltaic modules are also disclosed.Type: ApplicationFiled: January 14, 2011Publication date: May 12, 2011Applicant: MiaSoleInventors: Steven Croft, Randy Dorn, Ilan Gur, Bruce Hachtmann, Dennis Hollars, Shefali Jaiswal, Puthur Paulson, David Pearce, Kannan Ramanathan, William Sanders, Ben Tarbell
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Patent number: 7783744Abstract: To facilitate gathering of information required for root cause analysis associated with the abnormal behavior of an attribute (“problem attribute”), a user can specify causation attributes associated with the problem attribute. When the abnormal behavior is detected for the problem attribute, the causation attributes are automatically polled and stored in a database. The user can later examine the values of the causation attributes to determine if there is a causal relationship to the abnormal behavior of the problem attribute.Type: GrantFiled: March 24, 2006Date of Patent: August 24, 2010Assignee: BMC Software, Inc.Inventors: Atul Garg, Joe Scarpelli, Dasari Subramanyeswara Rao, Anjaneyulu Ramakrishna Tadikamalla, Kartik Kumar Peyyeti, Kannan Ramanathan Kumba, Nagaraj Mysore Narayanarao
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Publication number: 20090014057Abstract: One photovoltaic module includes a plurality of photovoltaic cells and at least one device selected from a sensor, a data storage device and an indicator. Another photovoltaic module includes a plurality of photovoltaic cells and a flexible circuit configured to act as an antenna for electromagnetic radiation. Methods of using such photovoltaic modules are also disclosed.Type: ApplicationFiled: July 13, 2007Publication date: January 15, 2009Inventors: Steven Croft, Randy Dorn, Ilan Gur, Bruce Hachtmann, Dennis Hollars, Shefali Jaiswal, Puthur Paulson, David Pearce, Kannan Ramanathan, William Sanders, Ben Tarbell
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Patent number: 7179677Abstract: A process for making a thin film ZnO/Cu(InGa)Se2 solar cell without depositing a buffer layer and by Zn doping from a vapor phase, comprising: depositing Cu(InGa)Se2 layer on a metal back contact deposited on a glass substrate; heating the Cu(InGa)Se2 layer on the metal back contact on the glass substrate to a temperature range between about 100° C. to about 250° C.; subjecting the heated layer of Cu(InGa)Se2 to an evaporant species from a Zn compound; and sputter depositing ZnO on the Zn compound evaporant species treated layer of Cu(InGa)Se2.Type: GrantFiled: September 3, 2003Date of Patent: February 20, 2007Assignee: Midwest Research InstituteInventors: Kannan Ramanathan, Falah S. Hasoon, Sarah E. Asher, James Dolan, James C. Keane
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Publication number: 20050257825Abstract: A process for making a thin film ZnO/Cu(InGa)Se2 solar cell without depositing a buffer layer and by Zn doping from a vapor phase, comprising: depositing Cu(InGa)Se2 layer on a metal back contact deposited on a glass substrate; heating the Cu(InGa)Se2 layer on the metal back contact on the glass substrate to a temperature range between about 100° C. to about 250° C.; subjecting the heated layer of Cu(InGa)Se2 to an evaporant species from a Zn compound; and sputter depositing ZnO on the Zn compound evaporant species treated layer of Cu(InGa)Se2.Type: ApplicationFiled: September 3, 2003Publication date: November 24, 2005Inventors: Kannan Ramanathan, Falah Hasoon, Sarah Asher, James Dolan, James Keane
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Publication number: 20040024667Abstract: An apparatus for deciding credit, the apparatus comprising: a customer identification module adapted for generating customer identification data from salesperson input data; a customer financial data acquisition module adapted for transmitting the customer identification data to a financial data provider and receiving customer financial data from the financial data provider using a communications network; and a credit limit calculator adapted for calculating a credit limit from the customer financial data and from a reasoning model structure using Example Based Evidential Reasoning and for transmitting the credit limit to a credit provider using the communications network.Type: ApplicationFiled: July 31, 2002Publication date: February 5, 2004Inventors: James Patrick Quaile, Srinivas Bollapragada, Prasanthi Venkata Surya Phani Ganti, Kannan Ramanathan, Mark David Osborn
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Publication number: 20030229556Abstract: The invention provides for processing of data to determine the likelihood of default of an entity. The processing may comprise obtaining a data set relating to an entity, the data set including at least a first likelihood of default indicator (LDI) value and a second LDI value; determining a LDI rate of change, based on the first LDI value and the second LDI value, to provide a LDI slope value; and determining the likelihood of default of the entity based on the LDI slope value and the first LDI value.Type: ApplicationFiled: June 5, 2002Publication date: December 11, 2003Inventors: Radu Neagu, Kannan Ramanathan, Roger Hoerl, Jason Weisman, Chandrasekhar Pisupati, Sung-Ho J. Ahn, Michael Shaw
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Patent number: 5976614Abstract: A method for electroless deposition of Cu.sub.x In.sub.y Ga.sub.z Se.sub.n (x=0-2, y=0-2, z=0-2, n=0-3) precursor films and powders onto a metallic substrate comprising:preparing an aqueous bath solution of compounds selected from the group consisting of:I) a copper compound, a selenium compound, an indium compound and gallium compound; II) a copper compound, a selenium compound and an indium compound; III) a selenium compound, and indium compound and a gallium compound; IV) a selenium compound and a indium compound; and V) a copper compound and selenium compound; each compound being present in sufficient quantity to react with each other to produce Cu.sub.x In.sub.y Ga.sub.z Se.sub.n (x=0-2, y=0-2, z=0-2, n=0-3);adjusting the pH of the aqueous bath solution to an acidic value by the addition of a dilute acid; andinitiating an electroless reaction with an oxidizing counterelectrode for a sufficient time to cause a deposit of Cu.sub.x In.sub.y Ga.sub.z Se.sub.Type: GrantFiled: October 13, 1998Date of Patent: November 2, 1999Assignee: Midwest Research InstituteInventors: Raghu N. Bhattacharya, Wendi Kay Batchelor, Holm Wiesner, Kannan Ramanathan, Rommel Noufi
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Patent number: 5871630Abstract: 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: GrantFiled: June 5, 1997Date of Patent: February 16, 1999Assignee: Davis, Joseph & NegleyInventors: Raghu N. Bhattacharya, Falah S. Hasoon, Holm Wiesner, James Keane, Rommel Noufi, Kannan Ramanathan
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Patent number: 5804054Abstract: 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: GrantFiled: November 26, 1997Date of Patent: September 8, 1998Assignee: Davis, Joseph & NegleyInventors: Raghu N. Bhattacharya, Miguel A. Contreras, James Keane, Andrew L. Tennant, John R. Tuttle, Kannan Ramanathan, Rommel Noufi
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Patent number: 5730852Abstract: 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: GrantFiled: December 12, 1995Date of Patent: March 24, 1998Assignee: Davis, Joseph & NegleyInventors: Raghu N. Bhattacharya, Miguel A. Contreras, James Keane, Andrew L. Tennant, John R. Tuttle, Kannan Ramanathan, Rommel Noufi