Patents by Inventor Robert M. Biefeld

Robert M. Biefeld 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: 6071109
    Abstract: A method for producing aluminum-indium-antimony materials by metal-organic chemical vapor deposition (MOCVD). This invention provides a method of producing Al.sub.X In.sub.1-x Sb crystalline materials by MOCVD wherein an Al source material, an In source material and an Sb source material are supplied as a gas to a heated substrate in a chamber, said Al source material, In source material, and Sb source material decomposing at least partially below 525.degree. C. to produce Al.sub.x In.sub.1-x Sb crystalline materials wherein x is greater than 0.002 and less than one.
    Type: Grant
    Filed: February 24, 1999
    Date of Patent: June 6, 2000
    Assignee: Sandia Corporation
    Inventors: Robert M. Biefeld, Andrew A. Allerman, Kevin C. Baucom
  • Patent number: 5995529
    Abstract: An infrared light source is disclosed that comprises a layered semiconductor active region having a semimetal region and at least one quantum-well layer. The semimetal region, formed at an interface between a GaAsSb or GalnSb layer and an InAsSb layer, provides electrons and holes to the quantum-well layer to generate infrared light at a predetermined wavelength in the range of 2-6 .mu.m. Embodiments of the invention can be formed as electrically-activated light-emitting diodes (LEDs) or lasers, and as optically-pumped lasers. Since the active region is unipolar, multiple active regions can be stacked to form a broadband or multiple-wavelength infrared light source.
    Type: Grant
    Filed: April 10, 1997
    Date of Patent: November 30, 1999
    Assignee: Sandia Corporation
    Inventors: Steven R. Kurtz, Robert M. Biefeld, Andrew A. Allerman
  • Patent number: 5625635
    Abstract: An infrared emitting device and method. The infrared emitting device comprises a III-V compound semiconductor substrate upon which are grown a quantum-well active region having a plurality of quantum-well layers formed of a ternary alloy comprising InAsSb sandwiched between barrier layers formed of a ternary alloy having a smaller lattice constant and a larger energy bandgap than the quantum-well layers. The quantum-well layers are preferably compressively strained to increase the threshold energy for Auger recombination; and a method is provided for determining the preferred thickness for the quantum-well layers. Embodiments of the present invention are described having at least one cladding layer to increase the optical and carrier confinement in the active region, and to provide for waveguiding of the light generated within the active region.
    Type: Grant
    Filed: November 28, 1994
    Date of Patent: April 29, 1997
    Assignee: Sandia Corporation
    Inventors: Steven R. Kurtz, Robert M. Biefeld, L. Ralph Dawson, Arnold J. Howard, Kevin C. Baucom
  • Patent number: 5065205
    Abstract: A high gain photoconductive device for 8 to 12 .mu.m wavelength radiation including an active semiconductor region extending from a substrate to an exposed face, the region comprising a strained-layer superlattice of alternating layers of two different InAs.sub.1-x Sb.sub.x compounds having x>0.75. A pair of spaced electrodes are provided on the exposed face, and changes in 8 to 12 .mu.m radiation on the exposed face cause a large photoconductive gain between the spaced electrodes.
    Type: Grant
    Filed: May 12, 1989
    Date of Patent: November 12, 1991
    Assignee: The United States of America as represented by the United States Department of Energy
    Inventors: Robert M. Biefeld, L. Ralph Dawson, Ian J. Fritz, Steven R. Kurtz, Thomas E. Zipperian
  • Patent number: 5032435
    Abstract: A system for monitoring and controlling the rate of growth of thin films in an atmosphere of reactant gases measures the UV absorbance of the atmosphere and calculates the partial pressure of the gases. The flow of reactant gases is controlled in response to the partial pressure.
    Type: Grant
    Filed: March 27, 1989
    Date of Patent: July 16, 1991
    Assignee: The United States of America as represented by the United States Department of Energy
    Inventors: Robert M. Biefeld, Gregory A. Hebner, Kevin P. Killeen, Steven P. Zuhoski
  • Patent number: 4947223
    Abstract: A semiconductor high reflector comprising a number of thin alternating layers of semiconductor materials is electrically tunable and may be used as a temperature insensitive semiconductor laser in a Fabry-Perot configuration.
    Type: Grant
    Filed: August 31, 1987
    Date of Patent: August 7, 1990
    Assignee: The United States of America as represented by the United States Department of Energy
    Inventors: Robert M. Biefeld, Timothy J. Drummond, Paul L. Gourley, Thomas E. Zipperian
  • Patent number: 4616241
    Abstract: A semiconductor optical device which includes a superlattice having direct transitions between conduction band and valence band states with the same wave vector, the superlattice being formed from a plurality of alternating layers of two or more different materials, at least the material with the smallest bandgap being an indirect bandgap material.
    Type: Grant
    Filed: March 22, 1983
    Date of Patent: October 7, 1986
    Assignee: The United States of America as represented by the United States Department of Energy
    Inventors: Robert M. Biefeld, Ian J. Fritz, Paul L. Gourley, Gordon C. Osbourn