Patents by Inventor Choong-Heui Chung

Choong-Heui Chung 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: 9780238
    Abstract: A metal-chalcogenide photovoltaic device includes a first electrode, a window layer spaced apart from the first electrode, and a photon-absorption layer between the first electrode and the window layer. The photon-absorption layer includes a metal-chalcogenide semiconductor. The window layer includes a layer of metal-oxide nanoparticles, and at least a portion of the window layer provides a second electrode that is substantially transparent to light within a range of operating wavelengths of the metal-chalcogenide photovoltaic device. A method of producing a metal-chalcogenide photovoltaic device includes providing a photovoltaic substructure, providing a solution of metal-oxide nanoparticles, and forming a window layer on the substructure using the solution of metal-oxide nanoparticles such that the window layer includes a layer of metal-oxide nanoparticles formed by a solution process.
    Type: Grant
    Filed: January 14, 2013
    Date of Patent: October 3, 2017
    Assignee: The Regents of the University of California
    Inventors: Yang Yang, Huanping Zhou, Bao Lei, Choong-Heui Chung, Brion P. Bob
  • Patent number: 9560754
    Abstract: An electro-optic device includes a substructure, a layer of nanowires deposited on the substructure so as to form a network of nanowires having electrically connected junctions at overlapping nanowire portions and defining spaces void of the nanowires, and a plurality of electrically conducting and optically transparent nanoparticles disposed to at least partially fill a plurality of the spaces to provide additional electrically conducting pathways for the network of nanowires across the spaces. The network of nanowires and the plurality of electrically conducting and optically transparent nanoparticles form at least a portion of an optically transparent electrode of the electro-optic device.
    Type: Grant
    Filed: October 15, 2012
    Date of Patent: January 31, 2017
    Assignee: THE JOHNS HOPKINS UNIVERSITY
    Inventors: Yang Yang, Choong-Heui Chung, Rui Zhu, Tze-Bin Song
  • Publication number: 20150349157
    Abstract: Provided is a thin film solar cell including: a substrate on which a rear surface electrode is formed; a light absorbing layer, which is a compound semiconductor, positioned on the rear surface electrode; and a composite layer positioned on the light absorbing layer and contacting the light absorbing layer, wherein the composite layer includes: a conductive mesh; and a semiconductor material filled in at least an empty space of the conductive mesh.
    Type: Application
    Filed: May 14, 2015
    Publication date: December 3, 2015
    Inventor: Choong-Heui Chung
  • Publication number: 20140326311
    Abstract: A metal-chalcogenide photovoltaic device includes a first electrode, a window layer spaced apart from the first electrode, and a photon-absorption layer between the first electrode and the window layer. The photon-absorption layer includes a metal-chalcogenide semiconductor. The window layer includes a layer of metal-oxide nanoparticles, and at least a portion of the window layer provides a second electrode that is substantially transparent to light within a range of operating wavelengths of the metal-chalcogenide photovoltaic device. A method of producing a metal-chalcogenide photovoltaic device includes providing a photovoltaic substructure, providing a solution of metal-oxide nanoparticles, and forming a window layer on the substructure using the solution of metal-oxide nanoparticles such that the window layer includes a layer of metal-oxide nanoparticles formed by a solution process.
    Type: Application
    Filed: January 14, 2013
    Publication date: November 6, 2014
    Applicant: The Regents of the University of California
    Inventors: Yang Yang, Huanping Zhou, Bao Lei, Choong-Heui Chung, Brion P. Bob
  • Publication number: 20140290987
    Abstract: An electro-optic device includes a substructure, a layer of nanowires deposited on the substructure so as to form a network of nanowires having electrically connected junctions at overlapping nanowire portions and defining spaces void of the nanowires, and a plurality of electrically conducting and optically transparent nanoparticles disposed to at least partially fill a plurality of the spaces to provide additional electrically conducting pathways for the network of nanowires across the spaces. The network of nanowires and the plurality of electrically conducting and optically transparent nanoparticles form at least a portion of an optically transparent electrode of the electro-optic device.
    Type: Application
    Filed: October 15, 2012
    Publication date: October 2, 2014
    Applicant: The Regents of the University of California
    Inventors: Yang Yang, Choong-Heui Chung, Rui Zhu, Tze-Bin Song
  • Patent number: 7642143
    Abstract: Provided are a method of fabricating a multilayered thin film transistor using a plastic substrate and an active matrix display device including the thin film transistor fabricated by the method. The method includes: preparing a substrate formed of plastic; forming a buffer insulating layer on the plastic substrate; forming a silicon layer on the buffer insulating layer; patterning the silicon layer to form an active layer; forming a gate insulating layer on the active layer; stacking a plurality of gate metal layers on the gate insulating layer; patterning the plurality of gate metal layers; and etching a corner region of the lowest gate metal layer formed on the gate insulating layer of the patterned gate metal layers. Accordingly, a gate metal is formed which includes a multilayered gate metal layer and has an etched corner region, thereby reducing an electric field of the corner to reduce a leakage current of the TFT.
    Type: Grant
    Filed: October 11, 2007
    Date of Patent: January 5, 2010
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Yong Hae Kim, Choong Heui Chung, Jae Hyun Moon, Yoon Ho Song
  • Publication number: 20080135837
    Abstract: Provided are a method of fabricating a multilayered thin film transistor using a plastic substrate and an active matrix display device including the thin film transistor fabricated by the method. The method includes: preparing a substrate formed of plastic; forming a buffer insulating layer on the plastic substrate; forming a silicon layer on the buffer insulating layer; patterning the silicon layer to form an active layer; forming a gate insulating layer on the active layer; stacking a plurality of gate metal layers on the gate insulating layer; patterning the plurality of gate metal layers; and etching a corner region of the lowest gate metal layer formed on the gate insulating layer of the patterned gate metal layers. Accordingly, a gate metal is formed which includes a multilayered gate metal layer and has an etched corner region, thereby reducing an electric field of the corner to reduce a leakage current of the TFT.
    Type: Application
    Filed: October 11, 2007
    Publication date: June 12, 2008
    Inventors: Yong Hae KIM, Choong Heui CHUNG, Jae Hyun MOON, Yoon Ho SONG
  • Patent number: 7379149
    Abstract: Provided are a low temperature active matrix display device using a plastic substrate and method of fabricating the same. The low temperature active matrix display device includes: a plastic substrate; a reflection layer disposed on the plastic substrate; a buffer layer disposed on the reflection layer; a thin film transistor disposed on the buffer layer in a first region of the plastic substrate; an interlayer dielectric layer disposed on the thin film transistor; a capacitor disposed in a trench formed in a second region of the plastic substrate and having a first electrode connected to a source electrode and a drain electrode of the thin film transistor, the trench extending from the interlayer dielectric layer to the reflection layer; and a display device having one electrode connected to a second electrode of the capacitor.
    Type: Grant
    Filed: October 28, 2005
    Date of Patent: May 27, 2008
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Yong Hae Kim, Choong Heui Chung, Jin Ho Lee
  • Patent number: 7309954
    Abstract: The present invention relates to a field emission display in which a gate plate having a gate hole and a gate electrode around the gate hole is formed between an anode plate having phosphor and a cathode plate having a field emitter and a control device for controlling field emission current, wherein the field emitter of the cathode plate is constructed to be opposite to the phosphor of the anode plate through the gate hole. According to the present invention, it is possible to significantly reduce the display row/column driving voltage by applying scan and data signals of the field emission display to the control device of each pixel, And the present invention is directed to improve the brightness of the field emission display in such a manner that the electric field necessary for field emission is applied through the gate electrode of the gate plate to freely control the distance between the anode plate and the cathode plate, so that a high voltage can be applied to the anode.
    Type: Grant
    Filed: December 23, 2003
    Date of Patent: December 18, 2007
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Yoon Ho Song, Chi Sun Hwang, Choong Heui Chung, Jin Ho Lee
  • Patent number: 7045469
    Abstract: A method of forming a buffer dielectric film in a semiconductor device and a method of manufacturing a thin film transistor using the same are disclosed.
    Type: Grant
    Filed: October 2, 2003
    Date of Patent: May 16, 2006
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Choong Yong Sohn, Yong Hae Kim, Jin Ho Lee, Young Wook Ko, Choong Heui Chung
  • Patent number: 6970149
    Abstract: An active matrix organic light emitting diode display panel circuit capable of reducing current and brightness nonuniformities between pixels by including a threshold voltage compensation circuit block between a data line and the pixels is provided. The threshold voltage of a video signal loaded in a data line is compensated for while the video signal passes through the threshold voltage compensation circuit block and then provided to a driving transistor of the pixels. One threshold voltage compensation circuit block is connected commonly to a plurality of pixels, rather than be connected to every pixel, so that threshold voltage compensation can be achieved for high-quality, large-sized displays, without increasing the number of transistors for the pixels.
    Type: Grant
    Filed: December 31, 2002
    Date of Patent: November 29, 2005
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Choong-heui Chung, Chi-sun Hwang, Yoon-ho Song, Jin-ho Lee
  • Patent number: 6958499
    Abstract: Provided is a field emission device having a mesh gate. The object of this research is to provide a field emission display (FED) using a triode field emission device for preventing increase of operation voltage, and securing high concentration of electron beams. The operation properties of the FED is different based on a structure of an extraction electrode. In this research, the extraction electrode is formed on the electron emitting source and it has a plurality of openings corresponding to the locations of carbon nanotube mixture. The concentration of the electron beams is raised and leakage current is suppressed by using an insulating mesh gate plate. The upper part of the openings has a smaller diagram than the lower part. The high concentration of electron beams and little leakage current can be generated by adding auxiliary electrodes or optimizing the shape of electrodes.
    Type: Grant
    Filed: September 30, 2003
    Date of Patent: October 25, 2005
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Chi-Sun Hwang, Yoon-Ho Song, Bong-Chul Kim, Choong-Heui Chung
  • Publication number: 20040160161
    Abstract: The present invention relates to a field emission display in which a gate plate having a gate hole and a gate electrode around the gate hole is formed between an anode plate having phosphor and a cathode plate having a field emitter and a control device for controlling field emission current, wherein the field emitter of the cathode plate is constructed to be opposite to the phosphor of the anode plate through the gate hole.
    Type: Application
    Filed: December 23, 2003
    Publication date: August 19, 2004
    Inventors: Yoon Ho Song, Chi Sun Hwang, Choong Heui Chung, Jin Ho Lee
  • Publication number: 20040121529
    Abstract: A method of forming a buffer dielectric film in a semiconductor device and a method of manufacturing a thin film transistor using the same are disclosed.
    Type: Application
    Filed: October 2, 2003
    Publication date: June 24, 2004
    Inventors: Choong Yong Sohn, Yong Hae Kim, Jin Ho Lee, Young Wook Ko, Choong Heui Chung
  • Publication number: 20040115870
    Abstract: Provided is a field emission device having a mesh gate. The object of this research is to provide a field emission display (FED) using a triode field emission device for preventing increase of operation voltage, and securing high concentration of electron beams. The operation properties of the FED is different based on a structure of an extraction electrode. In this research, the extraction electrode is formed on the electron emitting source and it has a plurality of openings corresponding to the locations of carbon nanotube mixture. The concentration of the electron beams is raised and leakage current is suppressed by using an insulating mesh gate plate. The upper part of the openings has a smaller diagram than the lower part. The high concentration of electron beams and little leakage current can be generated by adding auxiliary electrodes or optimizing the shape of electrodes.
    Type: Application
    Filed: September 30, 2003
    Publication date: June 17, 2004
    Inventors: Chi-Sun Hwang, Yoon-Ho Song, Bong-Chul Kim, Choong-Heui Chung
  • Publication number: 20040051685
    Abstract: An active matrix organic light emitting diode display panel circuit capable of reducing current and brightness nonuniformities between pixels by including a threshold voltage compensation circuit block between a data line and the pixels is provided. The threshold voltage of a video signal loaded in a data line is compensated for while the video signal passes through the threshold voltage compensation circuit block and then provided to a driving transistor of the pixels. One threshold voltage compensation circuit block is connected commonly to a plurality of pixels, rather than be connected to every pixel, so that threshold voltage compensation can be achieved for high-quality, large-sized displays, without increasing the number of transistors for the pixels.
    Type: Application
    Filed: December 31, 2002
    Publication date: March 18, 2004
    Inventors: Choong-Heui Chung, Chi-Sun Hwang, Yoon-Ho Song, Jin-Ho Lee
  • Patent number: 6410344
    Abstract: A ferroelectric random access memory (FeRAM) device including an active matrix provided with a transistor and diffusion regions, a first capacitor structure formed on a portion of the active matrix and provided with a first capacitor thin film made of strontium bismuth tantalate (SBT), a second capacitor structure formed on a remaining portion of the active matrix and provided with a second capacitor thin film made of lead zirconate titanate (PZT), and a metal interconnection formed on the first and the second capacitor structures, thereby electrically connecting the first and the second capacitor structures to one of the diffusion regions.
    Type: Grant
    Filed: December 14, 2000
    Date of Patent: June 25, 2002
    Assignee: Hyundai Electronics Industries Co., Ltd.
    Inventor: Choong-Heui Chung