Patents by Inventor Vijay Yelundur

Vijay Yelundur 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: 9153728
    Abstract: Solar cells and methods for their manufacture are disclosed. An example method may include providing a substrate comprising a base layer and introducing n-type dopant to the front surface of the base layer by ion implantation. The substrate may be annealed by heating the substrate to a temperature to anneal the implant damage and activate the introduced dopant, thereby forming an n-type doped layer into the front surface of the base layer. Oxygen may be introduced during the annealing step to form a passivating oxide layer on the n-type doped layer. Back contacts may be screen-printed on the back surface of the base layer, and a p-type doped layer may be formed at the interface of the back surface of the base layer and the back contacts during firing of the back contacts. The back contacts may provide an electrical connection to the p-type doped layer.
    Type: Grant
    Filed: January 9, 2012
    Date of Patent: October 6, 2015
    Assignee: Suniva, Inc.
    Inventors: Ajeet Rohatgi, Vijay Yelundur, Vinodh Chandrasekaran, Preston Davis, Ben Damiani
  • Patent number: 8921968
    Abstract: Solar cells and methods for their manufacture are disclosed. An example solar cell may comprise a substrate comprising a p-type base layer and an n-type selective emitter layer formed over the p-type base layer. The n-type selective emitter layer may comprise one or more first doped regions comprising implanted dopant and one or more second doped regions comprising diffused dopant. The one or more first doped regions may be more heavily doped than the one or more second doped regions. A p-n junction may be formed at the interface of the base layer and the selective emitter layer, such that the p-n junction and the selective emitter layer are both formed during a single anneal cycle.
    Type: Grant
    Filed: November 21, 2011
    Date of Patent: December 30, 2014
    Assignee: Suniva, Inc.
    Inventors: Ajeet Rohatgi, Vijay Yelundur, Preston Davis, Vinodh Chandrasekaran, Ben Damiani
  • Publication number: 20130247981
    Abstract: Solar cells, solar modules, and methods for their manufacture are disclosed. An example method may comprise forming a dielectric layer on at least one or more edges of a substrate, and then introducing dopant to at least one surface of the substrate. The substrate may be subjected to a heating process to at least drive the dopant to a predefined depth, thereby forming at least one of an emitter layer and a surface field layer. In the example method, the dielectric layer may not be removed during a subsequent manufacturing process. Associated solar cells and solar modules are also provided.
    Type: Application
    Filed: March 21, 2012
    Publication date: September 26, 2013
    Applicant: SUNIVA, INC.
    Inventors: VIJAY YELUNDUR, ATUL GUPTA, JASEN MOFFITT
  • Publication number: 20120279563
    Abstract: Interconnect apparatus and methods for their manufacture are disclosed. An example method for forming a solderable connection to a conductive surface may include forming one or more solderable metal regions on the conductive surface, for example an aluminum surface. The method may comprise applying a solder layer to the one or more solderable metal regions to form one or more soldered metal regions. The method may further comprise depositing one or more solderable metal regions on the conductive surface by plasma deposition. In other examples, the one or more solderable metal regions may be sputtered. Additionally, the method may comprise applying a flux to the one or more solderable metal regions prior to applying the solder layer to the one or more solderable metal regions. An interconnect ribbon may be soldered to at least one of the solder layer or the solderable metal regions. Associated interconnect apparatus are also provided.
    Type: Application
    Filed: May 2, 2011
    Publication date: November 8, 2012
    Inventors: Daniel Meier, Vijay Yelundur, Vinodh Chandrasekaran, Adam M. Payne, Sheri X. Wang
  • Publication number: 20120125416
    Abstract: Solar cells and methods for their manufacture are disclosed. An example solar cell may comprise a substrate comprising a p-type base layer and an n-type selective emitter layer formed over the p-type base layer. The n-type selective emitter layer may comprise one or more first doped regions comprising implanted dopant and one or more second doped regions comprising diffused dopant. The one or more first doped regions may be more heavily doped than the one or more second doped regions. A p-n junction may be formed at the interface of the base layer and the selective emitter layer, such that the p-n junction and the selective emitter layer are both formed during a single anneal cycle.
    Type: Application
    Filed: November 21, 2011
    Publication date: May 24, 2012
    Applicant: SUNIVA, INC.
    Inventors: AJEET ROHATGI, VIJAY YELUNDUR, PRESTON DAVIS, VINODH CHANDRASEKARAN, BEN DAMIANI
  • Publication number: 20120107998
    Abstract: Solar cells and methods for their manufacture are disclosed. An example method may include providing a substrate comprising a base layer and introducing n-type dopant to the front surface of the base layer by ion implantation. The substrate may be annealed by heating the substrate to a temperature to anneal the implant damage and activate the introduced dopant, thereby forming an n-type doped layer into the front surface of the base layer. Oxygen may be introduced during the annealing step to form a passivating oxide layer on the n-type doped layer. Back contacts may be screen-printed on the back surface of the base layer, and a p-type doped layer may be formed at the interface of the back surface of the base layer and the back contacts during firing of the back contacts. The back contacts may provide an electrical connection to the p-type doped layer.
    Type: Application
    Filed: January 9, 2012
    Publication date: May 3, 2012
    Applicant: SUNIVA, INC.
    Inventors: AJEET ROHATGI, VIJAY YELUNDUR, VINODH CHANDRASEKARAN, PRESTON DAVIS, BEN DAMIANI
  • Patent number: 8110431
    Abstract: Solar cells and methods for their manufacture are disclosed. An example method may include providing a p-type doped silicon substrate and introducing n-type dopant to a first and second region of the front surface of the substrate by ion implantation so that the second region is more heavily doped than the first region. The substrate may be subjected to a single high-temperature anneal cycle to activate the dopant, drive the dopant into the substrate, produce a p-n junction, and form a selective emitter. Oxygen may be introduced during the single anneal cycle to form in situ front and back passivating oxide layers. Fire-through of front and back contacts as well as metallization with contact connections may be performed in a single co-firing operation. Associated solar cells are also provided.
    Type: Grant
    Filed: June 3, 2010
    Date of Patent: February 7, 2012
    Assignee: Suniva, Inc.
    Inventors: Ajeet Rohatgi, Vijay Yelundur, Vinodh Chandrasekaran, Preston Davis, Ben Damiani
  • Patent number: 8071418
    Abstract: Solar cells and methods for their manufacture are disclosed. An example method may include providing a silicon substrate and introducing dopant to one or more selective regions of the front surface of the substrate by ion implantation. The substrate may be subjected to a single high-temperature anneal cycle. Additional dopant atoms may be introduced for diffusion into the front surface of the substrate during the single anneal cycle. A selective emitter may be formed on the front surface of the substrate such that the one or more selective regions of the selective emitter layer are more heavily doped than the remainder of the selective emitter layer. Associated solar cells are also provided.
    Type: Grant
    Filed: June 3, 2010
    Date of Patent: December 6, 2011
    Assignee: Suniva, Inc.
    Inventors: Ajeet Rohatgi, Vijay Yelundur, Preston Davis, Vinodh Chandrasekaran, Ben Damiani
  • Publication number: 20110139229
    Abstract: Solar cells and methods for their manufacture are disclosed. An example method may include providing a silicon substrate and introducing dopant to one or more selective regions of the front surface of the substrate by ion implantation. The substrate may be subjected to a single high-temperature anneal cycle. Additional dopant atoms may be introduced for diffusion into the front surface of the substrate during the single anneal cycle. A selective emitter may be formed on the front surface of the substrate such that the one or more selective regions of the selective emitter layer are more heavily doped than the remainder of the selective emitter layer. Associated solar cells are also provided.
    Type: Application
    Filed: June 3, 2010
    Publication date: June 16, 2011
    Inventors: Ajeet Rohatgi, Vijay Yelundur, Preston Davis, Vinodh Chandrasekaran, Ben Damiani
  • Publication number: 20110139231
    Abstract: Solar cells and methods for their manufacture are disclosed. An example method may include fabricating an n-type silicon substrate and introducing n-type dopant to one or more first and second regions of the substrate so that the second region is more heavily doped than the first region. The substrate may be subjected to a single high-temperature anneal cycle to form a selective front surface field layer. Oxygen may be introduced during the single anneal cycle to form in situ front and back passivating oxide layers. Fire-through of front and back contacts as well as metallization with contact connections may be performed in a single co-firing operation. The firing of the back contact may form a p+ emitter layer at the interface of the substrate and back contacts, thus forming a p-n junction at the interface of the emitter layer and the substrate. Associated solar cells are also provided.
    Type: Application
    Filed: August 25, 2010
    Publication date: June 16, 2011
    Inventors: Daniel Meier, Ajeet Rohatgi, Vinodh Chandrasekaran, Vijay Yelundur, Preston Davis, Ben Damiani
  • Publication number: 20110139230
    Abstract: Solar cells and methods for their manufacture are disclosed. An example method may include providing a p-type doped silicon substrate and introducing n-type dopant to a first and second region of the front surface of the substrate by ion implantation so that the second region is more heavily doped than the first region. The substrate may be subjected to a single high-temperature anneal cycle to activate the dopant, drive the dopant into the substrate, produce a p-n junction, and form a selective emitter. Oxygen may be introduced during the single anneal cycle to form in situ front and back passivating oxide layers. Fire-through of front and back contacts as well as metallization with contact connections may be performed in a single co-firing operation. Associated solar cells are also provided.
    Type: Application
    Filed: June 3, 2010
    Publication date: June 16, 2011
    Inventors: Ajeet Rohatgi, Vijay Yelundur, Vinodh Chandrasekaran, Preston Davis, Ben Damiani
  • Publication number: 20100233840
    Abstract: Devices, solar cell structures, and methods of fabrication thereof, are disclosed. Briefly described, one exemplary embodiment of the device, among others, includes: a co-fired p-type silicon substrate, wherein the bulk lifetime is about 20 to 125 ?s; an n+ layer formed on the top-side of the p-silicon substrate; a silicon nitride anti-reflective (AR) layer positioned on the top-side of the n+ layer; a plurality of Ag contacts positioned on portions of the silicon nitride AR layer, wherein the Ag contacts are in electronic communication with the n+-type emitter layer; an uniform Al back-surface field (BSF or p+) layer positioned on the back-side of the p-silicon substrate on the opposite side of the p-type silicon substrate as the n+ layer; and an Al contact layer positioned on the back-side of the Al BSF layer. The device has a fill factor (FF) of about 0.75 to 0.85, an open circuit voltage (VOC) of about 600 to 650 mV, and a short circuit current (JSC) of about 28 to 36 mA/cm2.
    Type: Application
    Filed: April 12, 2010
    Publication date: September 16, 2010
    Inventors: Ajeet Rohatgi, Ji-Weon Jeong, Kenta Nakayashiki, Vijay Yelundur, Dong Seop Kim, Mohamed Hilali
  • Publication number: 20090007965
    Abstract: Devices, solar cell structures, and methods of fabrication thereof, are disclosed.
    Type: Application
    Filed: June 12, 2008
    Publication date: January 8, 2009
    Applicant: Georgia Tech Research Corporation
    Inventors: Ajeet Rohatgi, Abasifreke Ebong, Vijay Yelundur
  • Publication number: 20080241986
    Abstract: Devices, solar cell structures, and methods of fabrication thereof, are disclosed.
    Type: Application
    Filed: June 12, 2008
    Publication date: October 2, 2008
    Applicant: Georgia Tech Research Corporation
    Inventors: Ajeet Rohatgi, Abasifreke Ebong, Vijay Yelundur
  • Publication number: 20080241988
    Abstract: Devices, solar cell structures, and methods of fabrication thereof, are disclosed.
    Type: Application
    Filed: June 12, 2008
    Publication date: October 2, 2008
    Applicant: Georgia Tech Research Corporation
    Inventors: Ajeet Rohatgi, Abasifreke Ebong, Vijay Yelundur
  • Publication number: 20080241987
    Abstract: Devices, solar cell structures, and methods of fabrication thereof, are disclosed.
    Type: Application
    Filed: June 12, 2008
    Publication date: October 2, 2008
    Applicant: Georgia Tech Research Corporation
    Inventors: Ajeet Rohatgi, Abasifreke Ebong, Vijay Yelundur
  • Publication number: 20050252544
    Abstract: Devices, solar cell structures, and methods of fabrication thereof, are disclosed.
    Type: Application
    Filed: May 11, 2005
    Publication date: November 17, 2005
    Inventors: Ajeet Rohatgi, Abasifreke Ebong, Vijay Yelundur
  • Publication number: 20050189015
    Abstract: Devices, solar cell structures, and methods of fabrication thereof, are disclosed. Briefly described, one exemplary embodiment of the device, among others, includes: a co-fired p-type silicon substrate, wherein the bulk lifetime is about 20 to 125 ?s; an n+ layer formed on the top-side of the p-silicon substrate; a silicon nitride anti-reflective (AR) layer positioned on the top-side of the n+ layer; a plurality of Ag contacts positioned on portions of the silicon nitride AR layer, wherein the Ag contacts are in electronic communication with the n+-type emitter layer; an uniform Al back-surface field (BSF or p+) layer positioned on the back-side of the p-silicon substrate on the opposite side of the p-type silicon substrate as the n+ layer; and an Al contact layer positioned on the back-side of the Al BSF layer. The device has a fill factor (FF) of about 0.75 to 0.85, an open circuit voltage (VOC) of about 600 to 650 mV, and a short circuit current (JSC) of about 28 to 36 mA/cm2.
    Type: Application
    Filed: October 29, 2004
    Publication date: September 1, 2005
    Inventors: Ajeet Rohatgi, Ji-Weon Jeong, Kenta Nakayashiki, Vijay Yelundur, Dong Seop Kim, Mohamed Hilali