Patents by Inventor Ghavam G. Shahidi

Ghavam G. Shahidi 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).

  • Publication number: 20180301586
    Abstract: A method of forming an electrical device that includes epitaxially growing a first conductivity type semiconductor material of a type III-V semiconductor on a semiconductor substrate. The first conductivity type semiconductor material continuously extending along an entirety of the semiconductor substrate in a plurality of triangular shaped islands; and conformally forming a layer of type III-V semiconductor material having a second conductivity type on the plurality of triangular shaped islands to provide a textured surface of a photovoltaic device. A light emitting diode is formed on the textured surface of the photovoltaic device.
    Type: Application
    Filed: April 2, 2018
    Publication date: October 18, 2018
    Inventors: Stephen W. Bedell, Ning Li, Devendra K. Sadana, Ghavam G. Shahidi
  • Publication number: 20180301587
    Abstract: A method of forming an electrical device that includes epitaxially growing a first conductivity type semiconductor material of a type III-V semiconductor on a semiconductor substrate. The first conductivity type semiconductor material continuously extending along an entirety of the semiconductor substrate in a plurality of triangular shaped islands; and conformally forming a layer of type III-V semiconductor material having a second conductivity type on the plurality of triangular shaped islands to provide a textured surface of a photovoltaic device. A light emitting diode is formed on the textured surface of the photovoltaic device.
    Type: Application
    Filed: April 9, 2018
    Publication date: October 18, 2018
    Inventors: Stephen W. Bedell, Ning Li, Devendra K. Sadana, Ghavam G. Shahidi
  • Publication number: 20180294238
    Abstract: A method of forming a semiconductor detector including: forming a p-n junction diode in an active device layer of a silicon-on-insulator (SOI) substrate, the active device layer being formed on an insulator layer of the SOI substrate; forming a first opening through the insulator layer to access a backside of a first doped region of the diode, the first doped region underlying a second doped region of the diode; forming a back contact on a back surface of the first doped region and electrically connecting with the first doped region; forming a conductive interconnect layer on an upper surface of the SOI substrate, the interconnect layer including a first top contact providing electrical connection with the second doped region; and forming an electrode in the first opening on the backside of the detector structure, the electrode providing electrical connection with the back contact of the diode.
    Type: Application
    Filed: April 11, 2017
    Publication date: October 11, 2018
    Inventors: Bahman Hekmatshoartabari, Ghavam G. Shahidi
  • Publication number: 20180287002
    Abstract: A photovoltaic device including a first cell positioned at a light receiving end of the photovoltaic device. The first cell has a first sequence of first semiconductor material layers of a first composition and the first junction has a first thickness. The photovoltaic device further includes at least a second cell positioned further from the light receiving end of the photovoltaic device than the first cell. Each cell in the at least one second cell has a greater thickness than the first thickness. The at least second cell comprising second semiconductor material layers in a second sequence equal to the first semiconductor material layers in the first sequence of the first cell.
    Type: Application
    Filed: December 6, 2017
    Publication date: October 4, 2018
    Inventors: Stephen W. Bedell, Ning Li, Devendra K. Sadana, Ghavam G. Shahidi
  • Publication number: 20180287001
    Abstract: A photovoltaic device including a first cell positioned at a light receiving end of the photovoltaic device. The first cell has a first sequence of first semiconductor material layers of a first composition and the first junction has a first thickness. The photovoltaic device further includes at least a second cell positioned further from the light receiving end of the photovoltaic device than the first cell. Each cell in the at least one second cell has a greater thickness than the first thickness. The at least second cell comprising second semiconductor material layers in a second sequence equal to the first semiconductor material layers in the first sequence of the first cell.
    Type: Application
    Filed: April 3, 2017
    Publication date: October 4, 2018
    Inventors: Stephen W. Bedell, Ning Li, Devendra K. Sadana, Ghavam G. Shahidi
  • Patent number: 10090562
    Abstract: A method for forming a thin film lithium ion battery includes, under a same vacuum seal, forming a stack of layers on a substrate including an anode layer, an electrolyte, a cathode layer and a first cap over the stack of layers to protect the layers from air. Under a same vacuum seal, the stack of layers is etched with a non-reactive etch process in accordance with a hardmask, and a second cap layer is formed over the stack of layers without breaking the vacuum seal. Contacts coupled to the cathode and the anode are formed.
    Type: Grant
    Filed: February 7, 2018
    Date of Patent: October 2, 2018
    Assignee: International Business Machines Corporation
    Inventors: Effendi Leobandung, Ghavam G. Shahidi
  • Publication number: 20180277707
    Abstract: An electrical device that includes a material stack present on a supporting substrate. An LED is present in a first end of the material stack having a first set of bandgap materials. A photovoltaic device is present in a second end of the material stack having a second set of bandgap materials. The first end of the material stack being a light receiving end, wherein a widest bandgap material for the first set of bandgap material is greater than a highest bandgap material for the second set of bandgap materials.
    Type: Application
    Filed: December 6, 2017
    Publication date: September 27, 2018
    Inventors: Stephen W. Bedell, Ning Li, Devendra K. Sadana, Ghavam G. Shahidi
  • Publication number: 20180277706
    Abstract: An electrical device that includes a material stack present on a supporting substrate. An LED is present in a first end of the material stack having a first set of bandgap materials. A photovoltaic device is present in a second end of the material stack having a second set of bandgap materials. The first end of the material stack being a light receiving end, wherein a widest bandgap material for the first set of bandgap material is greater than a highest bandgap material for the second set of bandgap materials.
    Type: Application
    Filed: March 24, 2017
    Publication date: September 27, 2018
    Inventors: Stephen W. Bedell, Ning Li, Devendra K. Sadana, Ghavam G. Shahidi
  • Publication number: 20180277705
    Abstract: An electrical device that includes a material stack present on a supporting substrate. An LED is present in a first end of the material stack having a first set of bandgap materials. A photovoltaic device is present in a second end of the material stack having a second set of bandgap materials. The first end of the material stack being a light receiving end, wherein a widest bandgap material for the first set of bandgap material is greater than a highest bandgap material for the second set of bandgap materials. A zinc oxide interface layer is present between the LED and the photovoltaic device. The zinc oxide layers or can also form a LED.
    Type: Application
    Filed: December 5, 2017
    Publication date: September 27, 2018
    Inventors: Stephen W. Bedell, Ning Li, Devendra K. Sadana, Ghavam G. Shahidi
  • Publication number: 20180277704
    Abstract: An electrical device that includes a material stack present on a supporting substrate. An LED is present in a first end of the material stack having a first set of bandgap materials. A photovoltaic device is present in a second end of the material stack having a second set of bandgap materials. The first end of the material stack being a light receiving end, wherein a widest bandgap material for the first set of bandgap material is greater than a highest bandgap material for the second set of bandgap materials. A zinc oxide interface layer is present between the LED and the photovoltaic device. The zinc oxide layers or can also form a LED.
    Type: Application
    Filed: March 24, 2017
    Publication date: September 27, 2018
    Inventors: Stephen W. Bedell, Ning Li, Devendra K. Sadana, Ghavam G. Shahidi
  • Patent number: 10082918
    Abstract: An apparatus includes multiple pixel circuits for touch and fingerprint detection that may be integrated with a touchscreen. Each pixel circuit includes a JFET with a gate connected to a capacitor plate, where the capacitor plate may be integrated with the gate, and where the capacitor plate is connected via a first diode to a corresponding select line. Furthermore, each JFET in the multiple pixel circuits has a source (or drain) connected to a corresponding read line and a drain (or source) connected via a second diode to a corresponding select line.
    Type: Grant
    Filed: November 8, 2016
    Date of Patent: September 25, 2018
    Assignee: International Business Machines Corporation
    Inventors: Bahman Hekmatshoartabari, Ghavam G. Shahidi
  • Patent number: 10079181
    Abstract: A method of forming a semiconductor structure includes forming a dummy gate above a semiconductor substrate. The dummy gate defines a source-drain region adjacent to the dummy gate and a channel region below the dummy gate. A silicon-germanium layer is epitaxially grown above the source-drain region with a target concentration of germanium atoms. The semiconductor structure is annealed to diffuse the germanium atoms from the silicon-germanium layer into the channel region to form a silicon-germanium channel region.
    Type: Grant
    Filed: January 10, 2017
    Date of Patent: September 18, 2018
    Assignee: International Business Machines Corporation
    Inventors: Kangguo Cheng, Ali Khakifirooz, Alexander Reznicek, Ghavam G. Shahidi
  • Publication number: 20180256314
    Abstract: High resolution active matrix nanowire circuits enable a flexible platform for artificial electronic skin having pressure sensing capability. Comb-like interdigitated nanostructures extending vertically from a pair of opposing, flexible assemblies facilitate pressure sensing via changes in resistance caused by varying the extent of contact among the interdigitated nanostructures. Electrically isolated arrays of vertically extending, electrically conductive nanowires or nanofins are formed from a doped, electrically conductive layer, each of the arrays being electrically connected to a transistor in an array of transistors. The nanowires or nanofins are interdigitated with further electrically conductive nanowires or nanofins mounted to a flexible handle.
    Type: Application
    Filed: May 12, 2018
    Publication date: September 13, 2018
    Inventors: Bahman Hekmatshoartabari, Ghavam G. Shahidi, Davood Shahrjerdi
  • Publication number: 20180258549
    Abstract: An epitaxy method includes providing an exposed crystalline region of a substrate material. Silicon is epitaxially deposited on the substrate material in a low temperature process wherein a deposition temperature is less than 500 degrees Celsius. A source gas is diluted with a dilution gas with a gas ratio of dilution gas to source gas of less than 1000.
    Type: Application
    Filed: May 10, 2018
    Publication date: September 13, 2018
    Inventors: BAHMAN HEKMATSHOAR-TABARI, ALI KHAKIFIROOZ, ALEXANDER REZNICEK, DEVENDRA K. SADANA, GHAVAM G. SHAHIDI, DAVOOD SHAHRJERDI
  • Patent number: 10068529
    Abstract: A pixel circuit includes a first capacitor and diode stage connected to a gate of a first transistor and ground, which receives a select input. A data line is coupled to a first source/drain of the first transistor, and a second source/drain of the first transistor is coupled to a gate of a second transistor. The second transistor has a drain connected to a supply voltage and a source connected to a resistor. The resistor connects to an organic light emitting diode (OLED), which connects to the ground.
    Type: Grant
    Filed: November 7, 2016
    Date of Patent: September 4, 2018
    Assignee: International Business Machines Corporation
    Inventors: Bahman Hekmatshoartabari, Ghavam G. Shahidi
  • Patent number: 10050166
    Abstract: A photovoltaic device including a single junction solar cell provided by an absorption layer of a type IV semiconductor material having a first conductivity, and an emitter layer of a type III-V semiconductor material having a second conductivity, wherein the type III-V semiconductor material has a thickness that is no greater than 50 nm.
    Type: Grant
    Filed: July 12, 2017
    Date of Patent: August 14, 2018
    Assignee: International Business Machines Corporation
    Inventors: Bahman Hekmatshoar-Tabari, Ali Khakifirooz, Devendra K. Sadana, Ghavam G. Shahidi, Davood Shahrjerdi
  • Patent number: 10043934
    Abstract: A photovoltaic device is provided in which the tunneling barrier for hole collection at either the front contact or the back contact of a silicon heterojunction cell is reduced, without compromising the surface passivation either the front contact or at the back contact. This is achieved in the present disclosure by replacing the intrinsic and/or doped hydrogenated amorphous silicon (a-Si:H) layer(s) at the back contact or at the front contact with an intrinsic and/or doped layer(s) of a semiconductor material having a lower valence band-offset than that of a:Si—H with c-Si, and/or a higher activated doping concentration compared to that of doped hydrogenated amorphous Si. The higher level of activated doping is due to the higher doping efficiency of the back contact or front contact semiconductor material compared to that of amorphous Si, and/or modulation doping of the back or front contact semiconducting material.
    Type: Grant
    Filed: June 8, 2011
    Date of Patent: August 7, 2018
    Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Bahman Hekmatshoar-Tabari, Devendra K. Sadana, Ghavam G. Shahidi, Davood Shahrjerdi
  • Patent number: 10043941
    Abstract: Provided is a light emitting semiconductor structure that operates as a light emitting diode (LED). In embodiments of the invention, the light emitting semiconductor structure includes a first barrier region, a second barrier region, and a single quantum well having a preselected thickness between the first barrier region and the second barrier region. The preselected thickness according to embodiments is selected to achieve a predetermined charge density in the quantum well. The predetermined charge density according to embodiments results from a predetermined bias current applied to the semiconductor structure. The predetermined bias current according to embodiments comprises less than about 1 mA.
    Type: Grant
    Filed: January 31, 2017
    Date of Patent: August 7, 2018
    Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Ning Li, Qinglong Li, Kunal Mukherjee, Devendra K. Sadana, Ghavam G. Shahidi
  • Publication number: 20180219122
    Abstract: Provided is a light emitting semiconductor structure that operates as a light emitting diode (LED). In embodiments of the invention, the light emitting semiconductor structure includes a first barrier region, a second barrier region, and a single quantum well having a preselected thickness between the first barrier region and the second barrier region. The preselected thickness according to embodiments is selected to achieve a predetermined charge density in the quantum well. The predetermined charge density according to embodiments results from a predetermined bias current applied to the semiconductor structure. The predetermined bias current according to embodiments comprises less than about 1 mA.
    Type: Application
    Filed: January 31, 2017
    Publication date: August 2, 2018
    Inventors: NING LI, QINGLONG LI, KUNAL MUKHERJEE, DEVENDRA K. SADANA, GHAVAM G. SHAHIDI
  • Patent number: 10038104
    Abstract: A junction field-effect transistor (JFET) with a gate region that includes two separate sub-regions having material of different conductivity types and/or a Schottky junction that substantially suppresses gate current when the gate junction is forward-biased, as well as complementary circuits that incorporate such JFET devices.
    Type: Grant
    Filed: December 13, 2016
    Date of Patent: July 31, 2018
    Assignee: International Business Machines Corporation
    Inventors: Bahman Hekmatshoartabari, Ghavam G. Shahidi