Patents by Inventor Steven P. Denbaars

Steven P. Denbaars 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: 9040327
    Abstract: A method for fabricating AlxGa1-xN-cladding-free nonpolar III-nitride based laser diodes or light emitting diodes. Due to the absence of polarization fields in the nonpolar crystal planes, these nonpolar devices have thick quantum wells that function as an optical waveguide to effectively confine the optical mode to the active region and eliminate the need for Al-containing waveguide cladding layers.
    Type: Grant
    Filed: June 13, 2012
    Date of Patent: May 26, 2015
    Assignee: The Regents of the University of California
    Inventors: Daniel F. Feezell, Mathew C. Schmidt, Kwang-Choong Kim, Robert M. Farrell, Daniel A. Cohen, James S. Speck, Steven P. DenBaars, Shuji Nakamura
  • Publication number: 20150115220
    Abstract: A nitride light emitting diode comprising at least one nitride-based active region formed on or above a patterned substrate, wherein the active region is comprised of at least one quantum well structure; and a nitride interlayer, formed on or above the active region, having at least two periods of alternating layers of InxGa1-xN and InyGa1-yN, where 0<x<1, 0?y<1 and x?y.
    Type: Application
    Filed: October 10, 2014
    Publication date: April 30, 2015
    Applicant: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Michael Iza, James S. Speck, Shuji Nakamura, Steven P. DenBaars
  • Publication number: 20150092386
    Abstract: A lighting apparatus for emitting polarized white light, which includes at least a first light source for emitting primary light comprised of one or more first wavelengths and having a first polarization direction; and at least a second light source for emitting secondary light in the first polarization direction, comprised of one or more secondary wavelengths, wherein the first light and the secondary light are combined to produce a polarized white light. The lighting apparatus may further comprise a polarizer for controlling the primary light's intensity, wherein a rotation of the polarizer varies an alignment of its polarization axis with respect to the first polarization direction, which varies transmission of the primary light through the polarizer, which controls a color co-ordinate or hue of the white light.
    Type: Application
    Filed: December 11, 2014
    Publication date: April 2, 2015
    Applicant: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Natalie N. Fellows-DeMille, Hisashi Masui, Steven P. DenBaars, Shuji Nakamura
  • Publication number: 20150048381
    Abstract: A method for the reuse of gallium nitride (GaN) epitaxial substrates uses band-gap-selective photoelectrochemical (PEC) etching to remove one or more epitaxial layers from bulk or free-standing GaN substrates without damaging the substrate, allowing the substrate to be reused for further growth of additional epitaxial layers. The method facilitates a significant cost reduction in device production by permitting the reuse of expensive bulk or free-standing GaN substrates.
    Type: Application
    Filed: September 22, 2014
    Publication date: February 19, 2015
    Applicant: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Casey O. Holder, Daniel F. Feezell, Steven P. DenBaars, Shuji Nakamura
  • Patent number: 8956896
    Abstract: A method of device growth and p-contact processing that produces improved performance for non-polar III-nitride light emitting diodes and laser diodes. Key components using a low defect density substrate or template, thick quantum wells, a low temperature p-type III-nitride growth technique, and a transparent conducting oxide for the electrodes.
    Type: Grant
    Filed: April 5, 2012
    Date of Patent: February 17, 2015
    Assignees: The Regents of the University of California, Japan Science and Technology Agency
    Inventors: Mathew C. Schmidt, Kwang Choong Kim, Hitoshi Sato, Steven P. DenBaars, James S. Speck, Shuji Nakamura
  • Publication number: 20150036337
    Abstract: A high-power, high-brightness lighting system for large venue lighting, which includes a laser diode as the excitation source and one or more phosphor materials placed at a remote distance from the laser source. The invention offers a lighting system with the advantages of high brightness, high efficiency, high luminous efficacy, long lifetimes, quick turn-on times, suitable color properties, environmental sustainability, and easy maintenance, which may allow for smart and flexible control over large area lighting systems with resulting savings in operating and maintenance costs.
    Type: Application
    Filed: July 31, 2014
    Publication date: February 5, 2015
    Applicant: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Kristin A. Denault, Steven P. DenBaars, Ram Seshadri
  • Publication number: 20150014732
    Abstract: This invention is related to LED Light Extraction for optoelectronic applications. More particularly the invention relates to (Al, Ga, In)N combined with optimized optics and phosphor layer for highly efficient (Al, Ga, In)N based light emitting diodes applications, and its fabrication method. A further extension is the general combination of a shaped high refractive index light extraction material combined with a shaped optical element.
    Type: Application
    Filed: September 11, 2014
    Publication date: January 15, 2015
    Applicant: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Natalie Fellows DeMille, Steven P. DenBaars, Shuji Nakamura
  • Publication number: 20140376584
    Abstract: An epitaxial structure for a III-Nitride based optical device, comprising an active layer with anisotropic strain on an underlying layer, where a lattice constant and strain in the underlying layer are partially or fully relaxed in at least one direction due to a presence of misfit dislocations, so that the anisotropic strain in the active layer is modulated by the underlying layer.
    Type: Application
    Filed: September 10, 2014
    Publication date: December 25, 2014
    Applicant: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Hiroaki Ohta, Feng Wu, Anurag Tyagi, Arpan Chakraborty, James S. Speck, Steven P. DenBaars, Shuji Nakamura, Erin C. Young
  • Publication number: 20140353707
    Abstract: A transparent light emitting diode (LED) includes a plurality of III-nitride layers, including an active region that emits light, wherein all of the layers except for the active region are transparent for an emission wavelength of the light, such that the light is extracted effectively through all of the layers and in multiple directions through the layers. Moreover, the surface of one or more of the III-nitride layers may be roughened, textured, patterned or shaped to enhance light extraction.
    Type: Application
    Filed: August 15, 2014
    Publication date: December 4, 2014
    Applicant: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Shuji Nakamura, Steven P. DenBaars, Hirokuni Asamizu
  • Publication number: 20140346542
    Abstract: A III-nitride light emitting diode (LED) and method of fabricating the same, wherein at least one surface of a semipolar or nonpolar plane of a III-nitride layer of the LED is textured, thereby forming a textured surface in order to increase light extraction. The texturing may be performed by plasma assisted chemical etching, photolithography followed by etching, or nano-imprinting followed by etching.
    Type: Application
    Filed: August 11, 2014
    Publication date: November 27, 2014
    Applicant: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Hong Zhong, Anurag Tyagi, Kenneth J. Vampola, James S. Speck, Steven P. DenBaars, Shuji Nakamura
  • Patent number: 8882935
    Abstract: A method for the fabrication of nonpolar indium gallium nitride (InGaN) films as well as nonpolar InGaN-containing device structures using metalorganic chemical vapor deposition (MOVCD). The method is used to fabricate nonpolar InGaN/GaN violet and near-ultraviolet light emitting diodes and laser diodes.
    Type: Grant
    Filed: June 4, 2013
    Date of Patent: November 11, 2014
    Assignees: The Regents of the University of California, The Japan Science and Technology Agency
    Inventors: Arpan Chakraborty, Benjamin A. Haskell, Stacia Keller, James S. Speck, Steven P. DenBaars, Shuji Nakamura, Umesh K. Mishra
  • Publication number: 20140318592
    Abstract: A method for enhancement of thermoelectric properties through polarization engineering. Internal electric fields created within a material are used to spatially confine electrons for the purpose of enhancing thermoelectric properties. Electric fields can be induced within a material by the presence of bound charges at interfaces. A combination of spontaneous and piezoelectric polarization can induce this interfacial charge. The fields created by these bound charges have the effect of confining charge carriers near these interfaces. By confining charge carriers to a channel where scattering centers can be deliberately excluded the electron mobility can be enhanced, thus enhancing thermoelectric power factor. Simultaneously, phonons will not be affected by the fields and thus will be subject to the many scattering centers present in the majority of the structure. This allows for simultaneous enhancement of power factor and reduction of thermal conductivity, thus improving the thermoelectric figure of merit, ZT.
    Type: Application
    Filed: December 14, 2012
    Publication date: October 30, 2014
    Applicant: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Alexander Sztein, John E. Bowers, Steven P. DenBaars
  • Patent number: 8866126
    Abstract: An epitaxial structure for a III-Nitride based optical device, comprising an active layer with anisotropic strain on an underlying layer, where a lattice constant and strain in the underlying layer are partially or fully relaxed in at least one direction due to a presence of misfit dislocations, so that the anisotropic strain in the active layer is modulated by the underlying layer.
    Type: Grant
    Filed: May 29, 2013
    Date of Patent: October 21, 2014
    Assignee: The Regents of the University of California
    Inventors: Hiroaki Ohta, Feng Wu, Anurag Tyagi, Arpan Chakraborty, James S. Speck, Steven P. DenBaars, Shuji Nakamura, Erin C. Young
  • Patent number: 8866149
    Abstract: A method for the reuse of gallium nitride (GaN) epitaxial substrates uses band-gap-selective photoelectrochemical (PEC) etching to remove one or more epitaxial layers from bulk or free-standing GaN substrates without damaging the substrate, allowing the substrate to be reused for further growth of additional epitaxial layers. The method facilitates a significant cost reduction in device production by permitting the reuse of expensive bulk or free-standing GaN substrates.
    Type: Grant
    Filed: February 14, 2013
    Date of Patent: October 21, 2014
    Assignee: The Regents of the University of California
    Inventors: Casey O. Holder, Daniel F. Feezell, Steven P. DenBaars, Shuji Nakamura
  • Publication number: 20140308769
    Abstract: A method for improving the growth morphology of (Ga,Al,In,B)N thin films on nonpolar or semipolar (Ga,Al,In,B)N substrates, wherein a (Ga,Al,In,B)N thin film is grown directly on a nonpolar or semipolar (Ga,Al,In,B)N substrate or template and a portion of the carrier gas used during growth is comprised of an inert gas. Nonpolar or semipolar nitride LEDs and diode lasers may be grown on the smooth (Ga,Al,In,B)N thin films grown by the present invention.
    Type: Application
    Filed: June 24, 2014
    Publication date: October 16, 2014
    Applicant: The Regents of the University of California
    Inventors: Robert M. Farrell, Michael Iza, James S. Speck, Steven P. DenBaars, Shuji Nakamura
  • Patent number: 8860051
    Abstract: This invention is related to LED Light Extraction for optoelectronic applications. More particularly the invention relates to (Al, Ga, In)N combined with optimized optics and phosphor layer for highly efficient (Al, Ga, In)N based light emitting diodes applications, and its fabrication method. A further extension is the general combination of a shaped high refractive index light extraction material combined with a shaped optical element.
    Type: Grant
    Filed: November 15, 2007
    Date of Patent: October 14, 2014
    Assignee: The Regents of the University of California
    Inventors: Natalie N. Fellows, Steven P. DenBaars, Shuji Nakamura
  • Publication number: 20140301419
    Abstract: A method of fabricating an (Al,Ga,In)N laser diode, comprising depositing one or more III-N layers upon a growth substrate at a first temperature, depositing an indium containing laser core at a second temperature upon layers deposited at a first temperature, and performing all subsequent fabrication steps under conditions that inhibit degradation of the laser core, wherein the conditions are a substantially lower temperature than the second temperature.
    Type: Application
    Filed: June 18, 2014
    Publication date: October 9, 2014
    Applicant: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Daniel A. Cohen, Steven P. DenBaars, Shuji Nakamura
  • Patent number: 8853669
    Abstract: A method of fabricating a substrate for a semipolar III-nitride device, comprising patterning and forming one or more mesas on a surface of a semipolar III-nitride substrate or epilayer, thereby forming a patterned surface of the semipolar III-nitride substrate or epilayer including each of the mesas with a dimension l along a direction of a threading dislocation glide, wherein the threading dislocation glide results from a III-nitride layer deposited heteroepitaxially and coherently on a non-patterned surface of the substrate or epilayer.
    Type: Grant
    Filed: October 26, 2011
    Date of Patent: October 7, 2014
    Assignee: The Regents of the University of California
    Inventors: James S. Speck, Anurag Tyagi, Steven P. Denbaars, Shuji Nakamura
  • Publication number: 20140291694
    Abstract: A nonpolar III-nitride film grown on a miscut angle of a substrate, in order to suppress the surface undulations, is provided. The surface morphology of the film is improved with a miscut angle towards an a-axis direction comprising a 0.15° or greater miscut angle towards the a-axis direction and a less than 30° miscut angle towards the a-axis direction.
    Type: Application
    Filed: June 16, 2014
    Publication date: October 2, 2014
    Applicant: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Asako Hirai, Zhongyuan Jia, Makoto Saito, Hisashi Yamada, Kenji Iso, Steven P. DenBaars, Shuji Nakamura, James S. Speck
  • Patent number: 8841691
    Abstract: A method of fabricating a Light Emitting Diode with improved light extraction efficiency, comprising depositing a plurality of Zinc Oxide (ZnO) nanorods on one or more surfaces of a III-Nitride based LED, by growing the ZnO nanorods from an aqueous solution, wherein the surfaces are different from c-plane surfaces of III-Nitride and transmit light generated by the LED.
    Type: Grant
    Filed: August 19, 2013
    Date of Patent: September 23, 2014
    Assignee: The Regents of the University of California
    Inventors: Jacob J. Richardson, Daniel B. Thompson, Ingrid Koslow, Jun-Seok Ha, Frederick F. Lange, Steven P. DenBaars, Shuji Nakamura