Patents by Inventor Raghu N. Bhattacharya

Raghu N. Bhattacharya 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: 9410259
    Abstract: An electroplating solution and method for producing an electroplating solution containing a gallium salt, an ionic compound and a solvent that results in a gallium thin film that can be deposited on a substrate.
    Type: Grant
    Filed: September 4, 2012
    Date of Patent: August 9, 2016
    Assignee: Alliance for Sustainable Energy, LLC
    Inventor: Raghu N. Bhattacharya
  • Patent number: 8809237
    Abstract: A method of forming a superconducting article includes providing a substrate tape, forming a superconducting layer overlying the substrate tape, and depositing a capping layer overlying the superconducting layer. The capping layer includes a noble metal and has a thickness not greater than about 1.0 micron. The method further includes electrodepositing a stabilizer layer overlying the capping layer using a solution that is non-reactive to the superconducting layer. The superconducting layer has an as-formed critical current IC(AF) and a post-stabilized critical current IC(PS). The IC(PS) is at least about 95% of the IC(AF).
    Type: Grant
    Filed: February 19, 2008
    Date of Patent: August 19, 2014
    Assignee: SuperPower, Inc.
    Inventors: Raghu N. Bhattacharya, Xun Zhang, Venkat Selvamanickam
  • Publication number: 20140202870
    Abstract: An electroplating solution and method for producing an electroplating solution containing a gallium salt, an ionic compound and a solvent that results in a gallium thin film that can be deposited on a substrate.
    Type: Application
    Filed: September 4, 2012
    Publication date: July 24, 2014
    Applicant: Alliance for Sustainable Energy, LLC
    Inventor: Raghu N. Bhattacharya
  • Publication number: 20140100112
    Abstract: Methods of producing one or more biaxially textured layer on a substrate, and articles produced by the methods, are disclosed. As exemplary method may comprise electrodepositing on the substrate a precursor material selected from the group consisting of rare earths, transition metals, actinides, lanthanides, and oxides thereof. An exemplary article may comprise a biaxially textured base material, and at least one biaxially textured layer selected from the group consisting of rare earths, transition metals, actinides, lanthanides, and oxides thereof. The at least one biaxially textured layer is formed by electrodeposition on the biaxially textured base material.
    Type: Application
    Filed: October 16, 2013
    Publication date: April 10, 2014
    Applicant: Alliance for Sustainable Energy, LLC
    Inventors: Raghu N. BHATTACHARYA, Sovannary PHOK, Priscila SPAGNOL, Tapas CHAUDHURI
  • Patent number: 8586506
    Abstract: Methods of producing one or more biaxially textured layer on a substrate, and articles produced by the methods, are disclosed. An exemplary method may comprise electrodepositing on the substrate a precursor material selected from the group consisting of rare earths, transition metals, actinide, lanthanides, and oxides thereof. An exemplary article (150) may comprise a biaxially textured base material (130), and at least one biaxially textured layer (110) selected from the group consisting of rare earths, transition metals, actinides, lanthanides, and oxides thereof. The at least one biaxially textured layer (110) is formed by electrodeposition on the biaxially textured base material (130).
    Type: Grant
    Filed: August 1, 2005
    Date of Patent: November 19, 2013
    Assignee: Alliance for Sustainable Energy, LLC
    Inventors: Raghu N. Bhattacharya, Sovannary Phok, Priscila Spagnol, Tapas Chaudhuri
  • Publication number: 20100167084
    Abstract: Methods of producing one or more biaxially textured layer on a substrate, and articles produced by the methods, are disclosed. An exemplary method may comprise electrodepositing on the substrate a precursor material selected from the group consisting of rare earths, transition metals, actinide, lanthanides, and oxides thereof. An exemplary article (150) may comprise a biaxially textured base material (130), and at least one biaxially textured layer (110) selected from the group consisting of rare earths, transition metals, actinides, lanthanides, and oxides thereof. The at least one biaxially textured layer (110) is formed by electrodeposition on the biaxially textured base material (130).
    Type: Application
    Filed: August 1, 2005
    Publication date: July 1, 2010
    Applicant: Midwest Research Institute
    Inventors: Raghu N. Bhattacharya, Sovannary Phok, Priscila Spagnol, Tapas Chaudhuri
  • Patent number: 7611573
    Abstract: The invention provides CBD ZnS/Zn(O,OH)S and spray deposited ZnS/Zn(O,OH)S buffer layers prepared from a solution of zinc salt, thiourea and ammonium hydroxide dissolved in a non-aqueous/aqueous solvent mixture or in 100% non-aqueous solvent. Non-aqueous solvents useful in the invention include methanol, isopropanol and triethyl-amine. One-step deposition procedures are described for CIS, CIGS and other solar cell devices.
    Type: Grant
    Filed: April 2, 2004
    Date of Patent: November 3, 2009
    Assignee: Alliance for Sustainable Energy, LLC
    Inventor: Raghu N. Bhattacharya
  • Publication number: 20090209429
    Abstract: A method of forming a superconducting article includes providing a substrate tape, forming a superconducting layer overlying the substrate tape, and depositing a capping layer overlying the superconducting layer. The capping layer includes a noble metal and has a thickness not greater than about 1.0 micron. The method further includes electrodepositing a stabilizer layer overlying the capping layer using a solution that is non-reactive to the superconducting layer. The superconducting layer has an as-formed critical current IC(AF) and a post-stabilized critical current IC(PS). The IC(PS) is at least about 95% of the IC(AF).
    Type: Application
    Filed: February 19, 2008
    Publication date: August 20, 2009
    Applicant: SUPERPOWER, INC.
    Inventors: Raghu N. Bhattacharya, Xun Zhang, Venkat Selvamanickam
  • Publication number: 20090191359
    Abstract: The invention provides CBD ZnS/Zn(O,OH)S and spray deposited ZnS/Zn(O,OH)S buffer layers prepared from a solution of zinc salt, thiourea and ammonium hydroxide dissolved in a non-aqueous/aqueous solvent mixture or in 100% non-aqueous solvent. Non-aqueous solvents useful in the invention include methanol, isopropanol and triethyl-amine. One-step deposition procedures are described for CIS, CIGS and other solar cell devices.
    Type: Application
    Filed: April 2, 2004
    Publication date: July 30, 2009
    Inventor: Raghu N. Bhattacharya
  • Publication number: 20040131792
    Abstract: A process for depositing copper-indium-gallium-selenide thin films on substrates, including foreign substrates, occurs in a chemical bath that includes a buffer solution and does not require external current as a catalyst. Formation of the chemical bath includes compounds of each of the constituent elements dissolved in deionized water and the addition of pHydrion buffers likewise dissolved. Deposition occurs as a result of the introduction of both a working electrode and a counter electrode. The deposited thin film is further processed through physical vapor deposition of additional indium, gallium, and selenium in order to fine-tune the stoichiometry of the resultant thin film.
    Type: Application
    Filed: June 17, 2003
    Publication date: July 8, 2004
    Inventor: Raghu N. Bhattacharya
  • Patent number: 6332967
    Abstract: Methods for preparing high quality superconducting oxide precursors which are well suited for further oxidation and annealing to form superconducting oxide films. The method comprises forming a multilayered superconducting precursor on a substrate by providing an electrodeposition bath comprising an electrolyte medium and a substrate electrode, and providing to the bath a plurality of precursor metal salts which are capable of exhibiting superconducting properties upon subsequent treatment. The superconducting precursor is then formed by electrodepositing a first electrodeposited (ED) layer onto the substrate electrode, followed by depositing a layer of silver onto the first electrodeposited (ED) layer, and then electrodepositing a second electrodeposited (ED) layer onto the Ag layer. The multilayered superconducting precursor is suitable for oxidation at a sufficient annealing temperature in air or an oxygen-containing atmosphere to form a crystalline superconducting oxide film.
    Type: Grant
    Filed: November 23, 1999
    Date of Patent: December 25, 2001
    Assignee: Midwest Research Institute
    Inventor: Raghu N. Bhattacharya
  • Patent number: 5976614
    Abstract: 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: Grant
    Filed: October 13, 1998
    Date of Patent: November 2, 1999
    Assignee: Midwest Research Institute
    Inventors: Raghu N. Bhattacharya, Wendi Kay Batchelor, Holm Wiesner, Kannan Ramanathan, Rommel Noufi
  • Patent number: 5948176
    Abstract: The present invention provides an economical, simple, dry and controllable semiconductor layer junction forming process to make cadmium free high efficiency photovoltaic cells having a first layer comprised primarily of copper indium diselenide having a thin doped copper indium diselenide n-type region, generated by thermal diffusion with a group II(b) element such as zinc, and a halide, such as chlorine, and a second layer comprised of a conventional zinc oxide bilayer. A photovoltaic device according the present invention includes a first thin film layer of semiconductor material formed primarily from copper indium diselenide. Doping of the copper indium diselenide with zinc chloride is accomplished using either a zinc chloride solution or a solid zinc chloride material. Thermal diffusion of zinc chloride into the copper indium diselenide upper region creates the thin n-type copper indium diselenide surface.
    Type: Grant
    Filed: September 29, 1997
    Date of Patent: September 7, 1999
    Assignee: Midwest Research Institute
    Inventors: Kannan V. Ramanathan, Miguel A. Contreras, Raghu N. Bhattacharya, James Keane, Rommel Noufi
  • 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
  • Patent number: 5462647
    Abstract: A process for the preparation of lead-zirconium-titanium (PZT) film and powder compositions. The process comprises the steps of providing an electrodeposition bath, providing soluble salts of lead, zirconium and titanium metals to this bath, electrically energizing the bath to thereby direct ions of each respective metal to a substrate electrode and cause formation of metallic particles as a recoverable film of PZT powder on the electrode, and also recovering the resultant film as a powder. Recovery of the PZT powder can be accomplished by continually energizing the bath to thereby cause powder initially deposited on the substrate-electrode to drop therefrom into the bath from which it is subsequently removed. A second recovery alternative comprises energizing the bath for a period of time sufficient to cause PZT powder deposition on the substrate-electrode only, from which it is subsequently recovered.
    Type: Grant
    Filed: September 9, 1994
    Date of Patent: October 31, 1995
    Assignee: Midwest Research Institute
    Inventors: Raghu N. Bhattacharya, David S. Ginley