Patents by Inventor Mary H. Crawford

Mary H. Crawford 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: 20220165888
    Abstract: A vertical gallium nitride (GaN) PN diode uses epitaxial growth of a thick drift region with a very low carrier concentration and a carefully designed multi-zone junction termination extension to achieve high voltage blocking and high-power efficiency. An exemplary large area (1 mm2) diode had a forward pulsed current of 3.5 A, an 8.3 m?-cm2 specific on-resistance, and a 5.3 kV reverse breakdown. A smaller area diode (0.063 mm2) was capable of 6.4 kV breakdown with a specific on-resistance of 10.2 m?-cm2, when accounting for current spreading through the drift region at a 45° angle.
    Type: Application
    Filed: January 10, 2022
    Publication date: May 26, 2022
    Inventors: Luke Yates, Brendan P. Gunning, Mary H. Crawford, Jeffrey Steinfeldt, Michael L. Smith, Vincent M. Abate, Jeramy R. Dickerson, Andrew M. Armstrong, Andrew Binder, Andrew A. Allerman, Robert J. Kaplar, Jack David Flicker, Gregory W. Pickrell
  • Patent number: 9059356
    Abstract: A p-type superlattice is used to laterally inject holes into an III-nitride multiple quantum well active layer, enabling efficient light extraction from the active area. Laterally-injected light-emitting diodes and laser diodes can enable brighter, more efficient devices that impact a wide range of wavelengths and applications. For UV wavelengths, applications include fluorescence-based biological sensing, epoxy curing, and water purification. For visible devices, applications include solid state lighting and projection systems.
    Type: Grant
    Filed: November 20, 2014
    Date of Patent: June 16, 2015
    Assignee: Sandia Corporation
    Inventors: Mary A. Miller, Mary H. Crawford, Andrew A. Allerman
  • Publication number: 20150144871
    Abstract: A p-type superlattice is used to laterally inject holes into an III-nitride multiple quantum well active layer, enabling efficient light extraction from the active area. Laterally-injected light-emitting diodes and laser diodes can enable brighter, more efficient devices that impact a wide range of wavelengths and applications. For UV wavelengths, applications include fluorescence-based biological sensing, epoxy curing, and water purification. For visible devices, applications include solid state lighting and projection systems.
    Type: Application
    Filed: November 20, 2014
    Publication date: May 28, 2015
    Inventors: Mary A. Miller, Mary H. Crawford, Andrew A. Allerman
  • Patent number: 8349633
    Abstract: A denticulated Group III nitride structure that is useful for growing AlxGa1-xN to greater thicknesses without cracking and with a greatly reduced threading dislocation (TD) density.
    Type: Grant
    Filed: May 26, 2009
    Date of Patent: January 8, 2013
    Assignee: Sandia Corporation
    Inventors: Andrew A. Allerman, Mary H. Crawford, Stephen R. Lee
  • Patent number: 7915626
    Abstract: A denticulated Group III nitride structure that is useful for growing AlxGa1-xN to greater thicknesses without cracking and with a greatly reduced threading dislocation (TD) density.
    Type: Grant
    Filed: August 15, 2006
    Date of Patent: March 29, 2011
    Assignee: Sandia Corporation
    Inventors: Andrew A. Allerman, Mary H. Crawford, Daniel D. Koleske, Stephen R. Lee
  • Patent number: 6665329
    Abstract: A visible light source device is described based on a light emitting diode and a nanocluster-based film. The light emitting diode utilizes a semiconductor quantum well structure between n-type and p-type semiconductor materials on the top surface a substrate such as sapphire. The nanocluster-based film is deposited on the bottom surface of the substrate and can be derived from a solution of MoS2, MoSe2, WS2, and WSe2 particles of size greater than approximately 2 nm in diameter and less than approximately 15 nm in diameter, having an absorption wavelength greater than approximately 300 nm and less than approximately 650 nm.
    Type: Grant
    Filed: June 6, 2002
    Date of Patent: December 16, 2003
    Assignee: Sandia Corporation
    Inventors: Mary H. Crawford, Jeffrey S. Nelson
  • Patent number: 6393038
    Abstract: A frequency-doubled semiconductor vertical-external-cavity surface-emitting laser (VECSEL) is disclosed for generating light at a wavelength in the range of 300-550 nanometers. The VECSEL includes a semiconductor multi-quantum-well active region that is electrically or optically pumped to generate lasing at a fundamental wavelength in the range of 600-1100 nanometers. An intracavity nonlinear frequency-doubling crystal then converts the fundamental lasing into a second-harmonic output beam. With optical pumping with 330 milliWatts from a semiconductor diode pump laser, about 5 milliWatts or more of blue light can be generated at 490 nm. The device has applications for high-density optical data storage and retrieval, laser printing, optical image projection, chemical-sensing, materials processing and optical metrology.
    Type: Grant
    Filed: October 4, 1999
    Date of Patent: May 21, 2002
    Assignee: Sandia Corporation
    Inventors: Thomas D. Raymond, William J. Alford, Mary H. Crawford, Andrew A. Allerman
  • Patent number: 5557627
    Abstract: A visible semiconductor laser. The visible semiconductor laser includes an InAlGaP active region surrounded by one or more AlGaAs layers on each side, with carbon as the sole p-type dopant. Embodiments of the invention are provided as vertical-cavity surface-emitting lasers (VCSELs) and as edge-emitting lasers (EELs). One or more transition layers comprised of a substantially indium-free semiconductor alloy such as AlAsP, AlGaAsP, or the like may be provided between the InAlGaP active region and the AlGaAS DBR mirrors or confinement layers to improve carrier injection and device efficiency by reducing any band offsets. Visible VCSEL devices fabricated according to the invention with a one-wavelength-thick (1.lambda.) optical cavity operate continuous-wave (cw) with lasing output powers up to 8 mW, and a peak power conversion efficiency of up to 11%.
    Type: Grant
    Filed: May 19, 1995
    Date of Patent: September 17, 1996
    Assignee: Sandia Corporation
    Inventors: Richard P. Schneider, Jr., Mary H. Crawford