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: 9153728Abstract: 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: GrantFiled: January 9, 2012Date of Patent: October 6, 2015Assignee: Suniva, Inc.Inventors: Ajeet Rohatgi, Vijay Yelundur, Vinodh Chandrasekaran, Preston Davis, Ben Damiani
-
Patent number: 8921968Abstract: 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: GrantFiled: November 21, 2011Date of Patent: December 30, 2014Assignee: Suniva, Inc.Inventors: Ajeet Rohatgi, Vijay Yelundur, Preston Davis, Vinodh Chandrasekaran, Ben Damiani
-
Publication number: 20130247981Abstract: 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: ApplicationFiled: March 21, 2012Publication date: September 26, 2013Applicant: SUNIVA, INC.Inventors: VIJAY YELUNDUR, ATUL GUPTA, JASEN MOFFITT
-
Publication number: 20120279563Abstract: 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: ApplicationFiled: May 2, 2011Publication date: November 8, 2012Inventors: Daniel Meier, Vijay Yelundur, Vinodh Chandrasekaran, Adam M. Payne, Sheri X. Wang
-
Publication number: 20120125416Abstract: 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: ApplicationFiled: November 21, 2011Publication date: May 24, 2012Applicant: SUNIVA, INC.Inventors: AJEET ROHATGI, VIJAY YELUNDUR, PRESTON DAVIS, VINODH CHANDRASEKARAN, BEN DAMIANI
-
Publication number: 20120107998Abstract: 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: ApplicationFiled: January 9, 2012Publication date: May 3, 2012Applicant: SUNIVA, INC.Inventors: AJEET ROHATGI, VIJAY YELUNDUR, VINODH CHANDRASEKARAN, PRESTON DAVIS, BEN DAMIANI
-
Patent number: 8110431Abstract: 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: GrantFiled: June 3, 2010Date of Patent: February 7, 2012Assignee: Suniva, Inc.Inventors: Ajeet Rohatgi, Vijay Yelundur, Vinodh Chandrasekaran, Preston Davis, Ben Damiani
-
Patent number: 8071418Abstract: 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: GrantFiled: June 3, 2010Date of Patent: December 6, 2011Assignee: Suniva, Inc.Inventors: Ajeet Rohatgi, Vijay Yelundur, Preston Davis, Vinodh Chandrasekaran, Ben Damiani
-
Publication number: 20110139229Abstract: 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: ApplicationFiled: June 3, 2010Publication date: June 16, 2011Inventors: Ajeet Rohatgi, Vijay Yelundur, Preston Davis, Vinodh Chandrasekaran, Ben Damiani
-
Publication number: 20110139231Abstract: 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: ApplicationFiled: August 25, 2010Publication date: June 16, 2011Inventors: Daniel Meier, Ajeet Rohatgi, Vinodh Chandrasekaran, Vijay Yelundur, Preston Davis, Ben Damiani
-
Publication number: 20110139230Abstract: 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: ApplicationFiled: June 3, 2010Publication date: June 16, 2011Inventors: Ajeet Rohatgi, Vijay Yelundur, Vinodh Chandrasekaran, Preston Davis, Ben Damiani
-
Publication number: 20100233840Abstract: 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: ApplicationFiled: April 12, 2010Publication date: September 16, 2010Inventors: Ajeet Rohatgi, Ji-Weon Jeong, Kenta Nakayashiki, Vijay Yelundur, Dong Seop Kim, Mohamed Hilali
-
Publication number: 20090007965Abstract: Devices, solar cell structures, and methods of fabrication thereof, are disclosed.Type: ApplicationFiled: June 12, 2008Publication date: January 8, 2009Applicant: Georgia Tech Research CorporationInventors: Ajeet Rohatgi, Abasifreke Ebong, Vijay Yelundur
-
Publication number: 20080241986Abstract: Devices, solar cell structures, and methods of fabrication thereof, are disclosed.Type: ApplicationFiled: June 12, 2008Publication date: October 2, 2008Applicant: Georgia Tech Research CorporationInventors: Ajeet Rohatgi, Abasifreke Ebong, Vijay Yelundur
-
Publication number: 20080241988Abstract: Devices, solar cell structures, and methods of fabrication thereof, are disclosed.Type: ApplicationFiled: June 12, 2008Publication date: October 2, 2008Applicant: Georgia Tech Research CorporationInventors: Ajeet Rohatgi, Abasifreke Ebong, Vijay Yelundur
-
Publication number: 20080241987Abstract: Devices, solar cell structures, and methods of fabrication thereof, are disclosed.Type: ApplicationFiled: June 12, 2008Publication date: October 2, 2008Applicant: Georgia Tech Research CorporationInventors: Ajeet Rohatgi, Abasifreke Ebong, Vijay Yelundur
-
Publication number: 20050252544Abstract: Devices, solar cell structures, and methods of fabrication thereof, are disclosed.Type: ApplicationFiled: May 11, 2005Publication date: November 17, 2005Inventors: Ajeet Rohatgi, Abasifreke Ebong, Vijay Yelundur
-
Publication number: 20050189015Abstract: 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: ApplicationFiled: October 29, 2004Publication date: September 1, 2005Inventors: Ajeet Rohatgi, Ji-Weon Jeong, Kenta Nakayashiki, Vijay Yelundur, Dong Seop Kim, Mohamed Hilali