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).
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Patent number: 9410259Abstract: 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: GrantFiled: September 4, 2012Date of Patent: August 9, 2016Assignee: Alliance for Sustainable Energy, LLCInventor: Raghu N. Bhattacharya
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Patent number: 8809237Abstract: 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: GrantFiled: February 19, 2008Date of Patent: August 19, 2014Assignee: SuperPower, Inc.Inventors: Raghu N. Bhattacharya, Xun Zhang, Venkat Selvamanickam
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Publication number: 20140202870Abstract: 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: ApplicationFiled: September 4, 2012Publication date: July 24, 2014Applicant: Alliance for Sustainable Energy, LLCInventor: Raghu N. Bhattacharya
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Publication number: 20140100112Abstract: 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: ApplicationFiled: October 16, 2013Publication date: April 10, 2014Applicant: Alliance for Sustainable Energy, LLCInventors: Raghu N. BHATTACHARYA, Sovannary PHOK, Priscila SPAGNOL, Tapas CHAUDHURI
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Patent number: 8586506Abstract: 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: GrantFiled: August 1, 2005Date of Patent: November 19, 2013Assignee: Alliance for Sustainable Energy, LLCInventors: Raghu N. Bhattacharya, Sovannary Phok, Priscila Spagnol, Tapas Chaudhuri
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Publication number: 20100167084Abstract: 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: ApplicationFiled: August 1, 2005Publication date: July 1, 2010Applicant: Midwest Research InstituteInventors: Raghu N. Bhattacharya, Sovannary Phok, Priscila Spagnol, Tapas Chaudhuri
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Patent number: 7611573Abstract: 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: GrantFiled: April 2, 2004Date of Patent: November 3, 2009Assignee: Alliance for Sustainable Energy, LLCInventor: Raghu N. Bhattacharya
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Publication number: 20090209429Abstract: 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: ApplicationFiled: February 19, 2008Publication date: August 20, 2009Applicant: SUPERPOWER, INC.Inventors: Raghu N. Bhattacharya, Xun Zhang, Venkat Selvamanickam
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Publication number: 20090191359Abstract: 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: ApplicationFiled: April 2, 2004Publication date: July 30, 2009Inventor: Raghu N. Bhattacharya
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Publication number: 20040131792Abstract: 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: ApplicationFiled: June 17, 2003Publication date: July 8, 2004Inventor: Raghu N. Bhattacharya
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Patent number: 6332967Abstract: 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: GrantFiled: November 23, 1999Date of Patent: December 25, 2001Assignee: Midwest Research InstituteInventor: Raghu N. Bhattacharya
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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: 5948176Abstract: 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: GrantFiled: September 29, 1997Date of Patent: September 7, 1999Assignee: Midwest Research InstituteInventors: Kannan V. Ramanathan, Miguel A. Contreras, Raghu N. Bhattacharya, James Keane, 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
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Patent number: 5550104Abstract: 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: GrantFiled: September 9, 1994Date of Patent: August 27, 1996Assignee: Davis, Joseph & NegleyInventor: Raghu N. Bhattacharya
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Patent number: 5462647Abstract: 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: GrantFiled: September 9, 1994Date of Patent: October 31, 1995Assignee: Midwest Research InstituteInventors: Raghu N. Bhattacharya, David S. Ginley