Patents by Inventor Robert Pang Heng Chang

Robert Pang Heng Chang 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: 5962132
    Abstract: A method of making silicon oxide nanoparticles possessing photoluminescence in the blue and green part of the visible spectrum when irradiated with ultraviolet (UV) light. The silicon oxide nanoparticles are formed in a chamber containing a direct current (dc) electric arc that generates a plasma in an oxygen-containing atmosphere. In the chamber, silicon is used as the anode, and the cathode can be copper (Cu) or tungsten (W). The use of silicon as an electrode is enabled by doping silicon with boron to a sufficiently high electronic conductivity, and orienting the two electrodes vertically in the chamber, so that the silicon anode is lowermost to contain silicon in the anode when it melts and vaporizes in the arc. The silicon oxide nanoparticles are collected on a cold plate adjacent to the arc.
    Type: Grant
    Filed: January 8, 1998
    Date of Patent: October 5, 1999
    Assignee: Northwestern University
    Inventors: Robert Pang Heng Chang, Jeffrey Michael Lauerhaas, Tobin Jay Marks, Udo C. Pernisz
  • Patent number: 5770022
    Abstract: A method of making silicon oxide nanoparticles possessing photoluminescence in the blue and green part of the visible spectrum when irradiated with ultraviolet (UV) light. The silicon oxide nanoparticles are formed in a chamber containing a direct current (dc) electric arc that generates a plasma in an oxygen-containing atmosphere. In the chamber, silicon is used as the anode, and the cathode can be copper (Cu) or tungsten (W). The use of silicon as an electrode is enabled by doping silicon with boron to a sufficiently high electronic conductivity, and orienting the two electrodes vertically in the chamber, so that the silicon anode is lowermost to contain silicon in the anode when it melts and vaporizes in the arc. The silicon oxide nanoparticles are collected on a cold plate adjacent to the arc.
    Type: Grant
    Filed: June 5, 1997
    Date of Patent: June 23, 1998
    Assignees: Dow Corning Corporation, Northwestern University
    Inventors: Robert Pang Heng Chang, Jeffrey Michael Lauerhaas, Tobin Jay Marks, Udo C. Pernisz
  • Patent number: 4062747
    Abstract: An amorphous, stoichiometric, native, semiconductor oxide layer, with a sharp interface between the oxide layer and the substrate, is grown by directing electrons toward a semiconductor substrate in the presence of oxygen. The source of electrons may be a simple filament. This invention may be implemented with standard plasma growth techniques by extracting the electrons from the plasma production region and directing them to the substrate.
    Type: Grant
    Filed: June 15, 1976
    Date of Patent: December 13, 1977
    Assignee: Bell Telephone Laboratories, Incorporated
    Inventors: Robert Pang Heng Chang, Ashok Kumar Sinha