Patents by Inventor Krishnakumar VELAPPAN

Krishnakumar VELAPPAN 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: 11978816
    Abstract: Object of the invention is to provide a new thin film device comprising at least one thin film cell, wherein the thin film cell comprises a first electrode, a photoactive layer and a second electrode, wherein the photoactive layer is arranged between the first and the second electrode, wherein at least one additional conductive line is arranged within an active area of the thin film cell and included in the photoactive layer and electrically interconnected with the first electrode and electrically insulated from the second electrode. Furthermore, the invention provides a method of forming a thin film device comprising at least one thin film cell, wherein the thin film cell comprises a first electrode, a photoactive layer and a second electrode and the photoactive layer is arranged between the first and the second electrode.
    Type: Grant
    Filed: November 30, 2017
    Date of Patent: May 7, 2024
    Assignees: China Triumph International Engineering Co., Ltd., CTF Solar GmbH
    Inventors: Shou Peng, Michael Harr, Xinjian Yin, Ganhua Fu, Krishnakumar Velappan, Bastian Siepchen
  • Patent number: 11563138
    Abstract: The present invention proposes a method to form a CdSeTe thin film with a defined amount of selenium and with a high quality. The method comprises the steps of providing a base substrate and of depositing a partial CdSeTe layer on a first portion of the base substrate. The step of depositing a partial CdSeTe layer is performed at least twice, wherein a predetermined time period without deposition of a partial CdSeTe layer on the first portion of the base substrate is provided between two subsequent steps of depositing a partial CdSeTe layer. The temperature of the base substrate and the CdSeTe layer already deposited on the first portion of the base substrate is controlled during the predetermined time period such that re-evaporation of Cd and/or Te from the CdSeTe layer already deposited takes place.
    Type: Grant
    Filed: August 8, 2019
    Date of Patent: January 24, 2023
    Assignees: CHINA TRIUMPH INTERNATIONAL ENGINEERING CO., LTD., CTF SOLAR GMBH
    Inventors: Shou Peng, Xinjian Yin, Ganhua Fu, Krishnakumar Velappan, Michael Harr, Bastian Siepchen
  • Publication number: 20220352408
    Abstract: The present invention proposes a method to form a CdSeTe thin film with a defined amount of selenium and with a high quality. The method comprises the steps of providing a base substrate and of depositing a partial CdSeTe layer on a first portion of the base substrate. The step of depositing a partial CdSeTe layer is performed at least twice, wherein a predetermined time period without deposition of a partial CdSeTe layer on the first portion of the base substrate is provided between two subsequent steps of depositing a partial CdSeTe layer. The temperature of the base substrate and the CdSeTe layer already deposited on the first portion of the base substrate is controlled during the predetermined time period such that re-evaporation of Cd and/or Te from the CdSeTe layer already deposited takes place.
    Type: Application
    Filed: August 8, 2019
    Publication date: November 3, 2022
    Applicants: CHINA TRIUMPH INTERNATIONAL ENGINEERING CO., LTD., CTF SOLAR GMBH
    Inventors: SHOU PENG, XINJIAN YIN, GANHUA FU, KRISHNAKUMAR VELAPPAN, MICHAEL HARR, BASTIAN SIEPCHEN
  • Patent number: 11217720
    Abstract: A method for depositing a CdTe layer on a substrate in a vacuum chamber by means of physical gas phase deposition is provided. The substrate is heated to a coating temperature before the deposition process and then guided past a vessel in which CdTe is converted into a vapour state, a gaseous component with an increased pressure (compared to the vacuum in the vacuum chamber) flowing through at least one inlet, against the substrate surface to be coated, such that the gaseous component is adsorbed on the substrate surface to be coated before the substrate is guided past the at least one vessel.
    Type: Grant
    Filed: February 3, 2017
    Date of Patent: January 4, 2022
    Assignees: FRAUNHOFER-GESELLSCHAFT ZUR FÖRDERUNG DER ANGEWANDTEN FORSCHUNG E.V., CTF SOLAR GMBH
    Inventors: Henry Morgner, Christoph Metzner, Daniel Hirsch, Olaf Zywitzki, Ludwig Decker, Torsten Werner, Bastian Siepchen, Bettina Späth, Krishnakumar Velappan, Christian Kraft, Christian Drost
  • Publication number: 20210013352
    Abstract: Object of the invention is to provide a new thin film device comprising at least one thin film cell, wherein the thin film cell comprises a first electrode, a photoactive layer and a second electrode, wherein the photoactive layer is arranged between the first and the second electrode, wherein at least one additional conductive line is arranged within an active area of the thin film cell and included in the photoactive layer and electrically interconnected with the first electrode and electrically insulated from the second electrode. Furthermore, the invention provides a method of forming a thin film device comprising at least one thin film cell, wherein the thin film cell comprises a first electrode, a photoactive layer and a second electrode and the photoactive layer is arranged between the first and the second electrode.
    Type: Application
    Filed: November 30, 2017
    Publication date: January 14, 2021
    Applicants: China Triumph International Engineering Co., Ltd., CTF Solar GmbH
    Inventors: Shou PENG, Michael HARR, Xinjian YIN, Ganhua FU, Krishnakumar VELAPPAN, Bastian SIEPCHEN
  • Publication number: 20190027634
    Abstract: A method for depositing a CdTe layer on a substrate in a vacuum chamber by means of physical gas phase deposition is provided. The substrate is heated to a coating temperature before the deposition process and then guided past a vessel in which CdTe is converted into a vapour state, a gaseous component with an increased pressure (compared to the vacuum in the vacuum chamber) flowing through at least one inlet, against the substrate surface to be coated, such that the gaseous component is adsorbed on the substrate surface to be coated before the substrate is guided past the at least one vessel.
    Type: Application
    Filed: February 3, 2017
    Publication date: January 24, 2019
    Applicants: Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V., CTF SOLAR GmbH
    Inventors: Henry Morgner, Christoph Metzner, Daniel Hirsch, Olaf Zywitzki, Ludwig Decker, Torsten Werner, Bastian Siepchen, Bettina Späth, Krishnakumar Velappan, Christian Kraft, Christian Drost
  • Patent number: 9960307
    Abstract: A method to produce thin film solar cells in superstrate or substrate configuration is an efficient way to minimize the loss due to absorption in CdS layer and to eliminate the CdCl2 activation treatment step. This is achieved by applying a sacrificial metal-halide layer between the CdS-layer and the CdTe-layer of the solar cells.
    Type: Grant
    Filed: August 27, 2014
    Date of Patent: May 1, 2018
    Assignees: China Triumph International Engineering Co., Ltd., CTF SOLAR GMBH
    Inventors: Krishnakumar Velappan, Bastian Siepchen, Bettina Späth, Christian Drost, Shou Peng
  • Patent number: 9899560
    Abstract: The present invention proposes a method to produce thin film CdTe solar cells having a pin-hole free and uniformly doped CdTe layer with a reduced layer thickness. The method according to the present invention is an efficient way to prevent shunting of the solar cells, to improve reliability and long-term stability of the solar cells and to provide a uniform doping of the CdTe layer. This is achieved by applying a sacrificial doping layer between a first CdTe layer having large grains and a second CdTe layer having small grains, which together form the CdTe layer of the solar cells. Furthermore it provides the possibility to eliminate the CdCl2 activation treatment step in case the sacrificial doping layer comprises a halogen.
    Type: Grant
    Filed: April 16, 2015
    Date of Patent: February 20, 2018
    Assignees: China Triumph International Engineering Co., Ltd., CTF Solar GmbH
    Inventors: Krishnakumar Velappan, Shou Peng
  • Publication number: 20160308086
    Abstract: The present invention proposes a method to produce thin film CdTe solar cells having a pin-hole free and uniformly doped CdTe layer with a reduced layer thickness. The method according to the present invention is an efficient way to prevent shunting of the solar cells, to improve reliability and long-term stability of the solar cells and to provide a uniform doping of the CdTe layer. This is achieved by applying a sacrificial doping layer between a first CdTe layer having large grains and a second CdTe layer having small grains, which together form the CdTe layer of the solar cells. Furthermore it provides the possibility to eliminate the CdCl2 activation treatment step in case the sacrificial doping layer comprises a halogen.
    Type: Application
    Filed: April 16, 2015
    Publication date: October 20, 2016
    Inventors: Krishnakumar Velappan, Shou Peng
  • Publication number: 20160240715
    Abstract: A method to produce thin film solar cells in superstrate or substrate configuration is an efficient way to minimize the loss due to absorption in CdS layer and to eliminate the CdCl2 activation treatment step. This is achieved by applying a sacrificial metal-halide layer between the CdS-layer and the CdTe-layer of the solar cells.
    Type: Application
    Filed: August 27, 2014
    Publication date: August 18, 2016
    Applicants: CHINA TRIUMPH INTERNATIONAL ENGINEERING CO., LTD., CTF SOLAR GMBH
    Inventors: Krishnakumar VELAPPAN, Bastian SIEPCHEN, Bettina SPÄTH, Christian DROST, Shou PENG