Patents by Inventor Prem Nath

Prem Nath 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: 5637537
    Abstract: A method of severing a thin film semiconductor device. The semiconductor device includes a substrate having a first electrode region formed thereon, a semiconductor body formed of layers of thin film semiconductor alloy material disposed upon the base electrode, a transparent, electrically conductive second electrode deposited atop the semiconductor body, and a containment layer of polymeric material associated with the first or second electrode in at least one region to permit subsequent severing of the device into a plurality of devices through said containment layer region.
    Type: Grant
    Filed: May 11, 1992
    Date of Patent: June 10, 1997
    Assignee: United Solar Systems Corporation
    Inventors: Prem Nath, Craig N. Vogeli
  • Patent number: 5474620
    Abstract: A composite laminate specifically adapted to protect the light incident surface of a photovoltaic module from cuts which could create a short circuit includes a plurality of stacked layer pairs. The first layer of each pair is a glass fiber material and the second layer is a thermoplastic. The layers are disposed in a mutually interpenetrating relationship and topped with a thin transparent protective layer, such as a layer of a fluoropolymer. this combination of layer pairs has been demonstrated to provide sufficient protection to meet Underwriters Laboratories specifications (UL 1703 Section 23. Cut Test) for flat plate photovoltaic modules and panels.
    Type: Grant
    Filed: May 16, 1994
    Date of Patent: December 12, 1995
    Assignee: United Solar Systems Corporation
    Inventors: Prem Nath, Craig N. Vogeli
  • Patent number: 5457057
    Abstract: Photovoltaic devices comprised of one or more encapsulated slabs of photovoltaic material are prepared by a process wherein a large area body of photovoltaic material is divided into a plurality of slabs. A photoactive area is defined within each slab, and defects therein passivated. Current collecting structures are affixed to each slab, and if the device includes a plurality of slabs, they are electrically interconnected. The front surfaces of the slabs are laminated with a transparent protective material, and the rear surfaces are bonded to a support plate. Also disclosed herein is a particular configuration of bus bar tape for interconnecting the slabs and an apparatus for preparing the current collecting wires.
    Type: Grant
    Filed: June 28, 1994
    Date of Patent: October 10, 1995
    Assignee: United Solar Systems Corporation
    Inventors: Prem Nath, Craig N. Vogeli, Timothy Barnard
  • Patent number: 5280133
    Abstract: A solar panel assembly (10) includes a power generating sheet (22) having two output terminals (30,32), and an electric cable (20) soldered at one end to terminals (30) and (32). A frame member is anchored to the solar panel in overlying relation to the terminals and an epoxy material (62) fills a cavity (58) defined by the frame member (40). A case (42) covers the frame member (40). The case includes an upper member (44) and a lower member (46) which are snap fitted together through apertures in the solar panel. The case (42) includes a tension relieving device which prevents tension on the cable (20) from being transferred to the cable end connected to the terminals (30) and (32). The epoxy provides a water resistant seal which allows the solar panel to be used in hostile environments.
    Type: Grant
    Filed: December 13, 1991
    Date of Patent: January 18, 1994
    Assignee: United Solar Systems Corporation
    Inventor: Prem Nath
  • Patent number: 5273608
    Abstract: A flexible encapsulated photovoltaic device is prepared by disposing photovoltaic devices on a sheet of thermoplastic material, disposing a front encapsulant material atop the devices, and disposing a bottom encapsulant layer so as to provide a multi-layered structure. The multi-layered structure is rolled under tension so as to compress the layers and the roll is heated to activate the thermoplastic material and bond the layers together. Additional layers may be interposed prior to rolling.
    Type: Grant
    Filed: February 6, 1992
    Date of Patent: December 28, 1993
    Assignee: United Solar Systems Corporation
    Inventor: Prem Nath
  • Patent number: 5268039
    Abstract: A photovoltaic device which is resistant to shunt and short circuit defects developing between the opposed electrodes thereof. The photovoltaic device comprises an electrically conductive substrate, a semiconductor body including a photogenerative region, a layer of transparent conductive material, and means for collecting photogenerated current. In particular, a layer of low-conductivity material is operatively positioned between the layer of transparent conductive material and the collecting means, thereby resistively restricting the flow of electric current through short circuit portions. A method of fabricating such a shunt-resistant photovoltaic device is also disclosed.
    Type: Grant
    Filed: March 19, 1993
    Date of Patent: December 7, 1993
    Assignee: United Solar Systems Corporation
    Inventors: Craig Vogeli, Prem Nath
  • Patent number: 5238519
    Abstract: Apparatus for simultaneously laminating thin polymeric sheets onto at least one surface of a plurality of spacedly disposed substrates, such as photovoltaic modules. By simultaneously accommodating the lamination of a plurality of modules, the cost of the back-end fabrication of those modules is substantially reduced. The apparatus includes a plurality of diaphragms adapted to forcibly and simultaneously urge the polymeric sheets against at least one surface of each of the respective modules to be laminated. The force is preferably generated by a pump which creates a vacuum between the diaphragm and the substrate surface.
    Type: Grant
    Filed: March 17, 1992
    Date of Patent: August 24, 1993
    Assignee: United Solar Systems Corporation
    Inventors: Prem Nath, Kenneth J. Whelan
  • Patent number: 5232518
    Abstract: A photovoltaic roofing system includes a plurality of roofing panels each having a photovoltaic device thereupon and each including an electrical connector engageable with a connector on another panel. The panels includes upstanding flanges and a batten and seam roof construction may be readily configured by interconnecting the panels, fastening them to the roof and covering adjoining flanges with the battens.
    Type: Grant
    Filed: January 16, 1992
    Date of Patent: August 3, 1993
    Assignee: United Solar Systems Corporation
    Inventors: Prem Nath, Timothy Laarman, Avtar Singh
  • Patent number: 5232519
    Abstract: A wireless, monolithic photovoltaic module. The module includes top and bottom, rectangular electrodes with a photovoltaic body and an adjacent insulating strip sandwiched in between the electrodes, the insulating strip being disposed proximate the edge of the bottom electrode. A bus bar overlies the insulating strip, but not the photovoltaic body, and is connected to a net of current carrying grid lines which overlie the photovoltaic body to form a current collector. A top encapsulating layer has diffractive grooves formed therein which overlie the grid lines to minimize shading effects otherwise caused by shadows from the grid lines.
    Type: Grant
    Filed: January 30, 1992
    Date of Patent: August 3, 1993
    Assignee: United Solar Systems Corporation
    Inventors: Troy Glatfelter, Craig Vogeli, Prem Nath
  • Patent number: 5228925
    Abstract: A photovoltaic window assembly suitable for use in building and vehicular applications. The window assembly includes an optically-transmissive substrate having one or more photovoltaic devices disposed thereon. A decorative template having cut-outs coextensive with each of the photovoltaic devices is disposed on the substrate such that the photovoltaic devices extend through the cut-outs. A window opening is also formed in the decorative template for transmission of light. An encapsulating layer is formed on the substrate, solar cells and decorative template to protect the solar cells and assembly from environmental damage and deterioration.
    Type: Grant
    Filed: December 23, 1991
    Date of Patent: July 20, 1993
    Assignee: United Solar Systems Corporation
    Inventors: Prem Nath, Avtar Singh
  • Patent number: 5181968
    Abstract: An improved photovoltaic device in which an electrically conductive adhesive is employed to affix the grid structure to the upper electrode thereof. By appropriately selecting the resistivity of the conductive adhesive, normal photogenerated current flow is readily accommodated, while shunted current flow, through patent or latent defects is substantially eliminated.
    Type: Grant
    Filed: June 24, 1991
    Date of Patent: January 26, 1993
    Assignee: United Solar Systems Corporation
    Inventors: Prem Nath, Craig Vogeli
  • Patent number: 5180434
    Abstract: In continuous apparatus for the glow discharge deposition of amorphous silicon alloy solar cells of p-i-n-type configuration in a plurality of interconnected, dedicated deposition chambers, a plasma bar operatively disposed between at least the plasma regions in which the layer pairs of amorphous silicon alloy material defining the major semiconductor junction of the solar cell are deposited. The plasma bar is adapted to initiate a plasma so as to prevent chemically adsorbed contaminants from deleteriously affecting the surface of the first deposited of the layer pair, thereby improving the open circuit voltage of the solar cell. In a similar manner, the plasma bar may also be provided between the layer pairs of amorphous silicon alloy material which combine to define the minor semiconductor junction of the solar cell. Finally, a plasma bar may be disposed between the oxide-based layer of a back reflector for reducing oxygen contamination of the silicon alloy material deposited thereupon.
    Type: Grant
    Filed: March 11, 1991
    Date of Patent: January 19, 1993
    Assignee: United Solar Systems Corporation
    Inventors: Gary M. DiDio, Kermit Jones, Kevin Hoffman, Timothy Laarman, Jon Call, Prem Nath
  • Patent number: 5176758
    Abstract: A light transmissive power generating photovoltaic device (14) includes a power generating film having a substrate (30), a plurality of semiconductor layers (30, 32, 34) and a transparent conductive oxide layer (37) with a grid adhered on the top surface thereof. Apertures (42) pass through the opaque semiconductive layers to let light pass through. The power generating film is laminated onto a transparent glass sheet (24, 26) on each side to form the photovoltaic device.
    Type: Grant
    Filed: May 20, 1991
    Date of Patent: January 5, 1993
    Assignee: United Solar Systems Corporation
    Inventors: Prem Nath, Craig Vogeli
  • Patent number: 5131954
    Abstract: Large area, thin-film body of photovoltaic material is subdivided into a plurality of small area devices. Through a selective etching process, a portion of the bottom electrode of each small area device is exposed. A metallic contact member is deposited upon the exposed portion of the electrode and a series connection between adjoining cells is established by interconnecting the metallic contact member of a first cell with the top electrode of an adjoining cell, so as to provide a large-area photovoltaic device including a plurality of interconnected sub-cells.
    Type: Grant
    Filed: November 25, 1991
    Date of Patent: July 21, 1992
    Assignee: United Solar Systems Corporation
    Inventors: Craig Vogeli, Prem Nath
  • Patent number: 5110370
    Abstract: A photovoltaic cell includes a light-directing optical element integrally formed in an encapsulant layer thereof in the region of opaque current-collecting gridlines.The optical element redirects light which would be absorbed by the opaque structure to other regions of the photovoltaic device, thereby decreasing shading effects.
    Type: Grant
    Filed: September 20, 1990
    Date of Patent: May 5, 1992
    Assignee: United Solar Systems Corporation
    Inventors: Craig Vogeli, Prem Nath
  • Patent number: 5101260
    Abstract: A multilayered, light-scattering back reflector for a photovoltaic device, said back reflector including a first relatively hard, textured layer atop a substrate and a second highly reflective layer conformally disposed atop the first layer. The back reflector may further include a third light scattering layer formed atop said second layer, said third layer adapted to further provide a barrier layer between the body of semiconductor material from which the photovoltaic device is formed and the multilayered back reflector.
    Type: Grant
    Filed: November 5, 1990
    Date of Patent: March 31, 1992
    Assignee: Energy Conversion Devices, Inc.
    Inventors: Prem Nath, John Call, Kevin Hoffman, Timothy D. Laarman, Gary DiDio
  • Patent number: 5092939
    Abstract: A roof structure 10 comprises panels 14 and 16 of desired length each having a galvanized steel supportive layer which has side supporting flanges 22 interconnected together to form the roof assembly 10. The mid portion 20 of each panel has a photovoltaic surface made from amorphous semiconductor material which is laminated onto the galvanized steel with a protective plastic transparent polymer coating laminated above the photovoltaic material. The laminated galvanized steel and the photovoltaic layers are rolled into a coil and transported on site where it is unrolled, cut to size having the flanges formed to construct the rigid panels and having the panels assembled together via clips 26 and weather-proof battens 32. The photovoltaic surfaces are connected together via electrical conduit 34 coupled through couplings 88 under the panels and between the frame members 30.
    Type: Grant
    Filed: November 30, 1990
    Date of Patent: March 3, 1992
    Assignee: United Solar Systems Corporation
    Inventors: Prem Nath, Timothy Laarman
  • Patent number: 5090356
    Abstract: An improved gas gate (34) is adapted to operatively interconnect to adjacent chambers in which process gases are introduced for depositing a first layer (16) upon a substrate (11) in a first chamber (28) and different process gases are introduced for depositing a second layer (18) in the second chamber (30) in continuous low pressure glow dicharge deposition process. A plurality of electrodes (60) and grounded shields (62) are positioned in the isolation passageway (92) of gas gate (34). The electrodes (60) have a potential sufficient to create a plasma from any gas molecule escaping from one of the deposition chambers. After the plasma is formed it is attracted to and captured or plated on the shield (62) preventing the gas plasma from landing on the substrate material (11) or passing through the gas gate.
    Type: Grant
    Filed: June 28, 1991
    Date of Patent: February 25, 1992
    Assignee: United Solar Systems Corporation
    Inventors: Prem Nath, Jon Call, Gary M. Didio, Kevin Hoffman
  • Patent number: 5084400
    Abstract: An electronic device of the type including a thin film body having a superposed metallic electrode has short circuit defects therein passivated by a conversion process in which the electrical resistivity of the metallic electrode material is increased proximate the defect regions. Conversion is accomplished by exposing the metallic electrode material to a conversion reagent and activating the reagent proximate the defect regions. The process may be utilized for a variety of differently configured devices, and may be readily adapted for use in a roll-to-roll device fabrication process.
    Type: Grant
    Filed: October 23, 1990
    Date of Patent: January 28, 1992
    Assignee: Energy Conversion Devices Inc.
    Inventors: Prem Nath, Craig N. Vogeli
  • Patent number: 4773944
    Abstract: A large area, high current, low voltage photovoltaic module including a common bottom electrode upon which a means adapted to collect and transport photogenerated current is disposed. By electrically interconnecting a plurality of said large area modules in series, the voltage obtained therefrom can be added so as to obtain any desired voltage output therefrom.
    Type: Grant
    Filed: September 8, 1987
    Date of Patent: September 27, 1988
    Assignee: Energy Conversion Devices, Inc.
    Inventors: Prem Nath, Timothy Laarman, Craig Vogeli, Kenneth Whelan, Bernard Kelly