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).

  • METHOD FOR THE REUSE OF GALLIUM NITRIDE EPITAXIAL SUBSTRATES
    Publication number: 20150371849
    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: August 28, 2015
    Publication date: December 24, 2015
    Applicant: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Casey O. Holder, Daniel F. Feezell, Steven P. DenBaars, Shuji Nakamura
  • Optical designs for high-efficacy white-light emitting diodes
    Patent number: 9219205
    Abstract: A method for increasing the luminous efficacy of a white light emitting diode (WLED), comprising introducing optically functional interfaces between an LED die and a phosphor, and between the phosphor and an outer medium, wherein at least one of the interfaces between the phosphor and the LED die provides a reflectance for light emitted by the phosphor away from the outer medium and a transmittance for light emitted by the LED die. Thus, a WLED may comprise a first material which surrounds an LED die, a phosphor layer, and at least one additional layer or material which is transparent for direct LED emission and reflective for the phosphor emission, placed between the phosphor layer and the first material which surrounds the LED die.
    Type: Grant
    Filed: December 6, 2013
    Date of Patent: December 22, 2015
    Assignee: The Regents of the University of California
    Inventors: Frederic S. Diana, Steven P. DenBaars, Shuji Nakamura
  • Semipolar or nonpolar nitride-based devices on partially or fully relaxed alloys with misfit dislocations at the heterointerface
    Patent number: 9159553
    Abstract: A dislocation-free high quality template with relaxed lattice constant, fabricated by spatially restricting misfit dislocation(s) around heterointerfaces. This can be used as a template layer for high In composition devices. Specifically, the present invention prepares high quality InGaN templates (In composition is around 5-10%), and can grow much higher In-composition InGaN quantum wells (QWs) (or multi quantum wells (MQWs)) on these templates than would otherwise be possible.
    Type: Grant
    Filed: August 23, 2010
    Date of Patent: October 13, 2015
    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
  • Method for the reuse of gallium nitride epitaxial substrates
    Patent number: 9147733
    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: September 22, 2014
    Date of Patent: September 29, 2015
    Assignee: The Regents of the University of California
    Inventors: Casey O. Holder, Daniel F. Feezell, Steven P. DenBaars, Shuji Nakamura
  • Structure and method for the fabrication of a gallium nitride vertical cavity surface emitting laser
    Patent number: 9136673
    Abstract: A III-Nitride based Vertical Cavity Surface Emitting Laser (VCSEL), wherein a cavity length of the VCSEL is controlled by etching.
    Type: Grant
    Filed: July 22, 2013
    Date of Patent: September 15, 2015
    Assignee: The Regents of the University of California
    Inventors: Casey O. Holder, Daniel F. Feezell, Steven P. DenBaars, James S. Speck, Shuji Nakamura
  • SEMI-POLAR III-NITRIDE OPTOELECTRONIC DEVICES ON M-PLANE SUBSTRATES WITH MISCUTS LESS THAN +/- 15 DEGREES IN THE C-DIRECTION
    Publication number: 20150255959
    Abstract: An optoelectronic device grown on a miscut of GaN, wherein the miscut comprises a semi-polar GaN crystal plane (of the GaN) miscut x degrees from an m-plane of the GaN and in a c-direction of the GaN, where ?15<x<?1 and 1<x<15 degrees.
    Type: Application
    Filed: May 26, 2015
    Publication date: September 10, 2015
    Applicant: THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
    Inventors: Po Shan Hsu, Kathryn M. Kelchner, Robert M. Farrell, Daniel A. Haeger, Hiroaki Ohta, Anurag Tyagi, Shuji Nakamura, Steven P. DenBaars, James S. Speck
  • Non-polar and semi-polar light emitting devices
    Patent number: 9130119
    Abstract: An (Al, Ga, In)N light emitting device, such as a light emitting diode (LED), in which high light generation efficiency is realized by fabricating the device on non-polar or semi-polar III-Nitride crystal geometries. Because non-polar and semi-polar emitting devices have significantly lower piezoelectric effects than c-plane emitting devices, higher efficiency emitting devices at higher current densities can be realized.
    Type: Grant
    Filed: December 11, 2007
    Date of Patent: September 8, 2015
    Assignees: The Regents of the University of California, Japan Science and Technology Agency
    Inventors: Steven P. DenBaars, Mathew C. Schmidt, Kwang Choong Kim, James S. Speck, Shuji Nakamura
  • HIGH-POWER, LASER-DRIVEN, WHITE LIGHT SOURCE USING ONE OR MORE PHOSPHORS
    Publication number: 20150226386
    Abstract: An efficient and stable, high-power, laser-driven white light source using one or more phosphors deposited on a thermally conductive substrate that is either transparent or reflective and placed at a remote distance from the laser source. The present invention relates generally to a high-power, laser-driven, white light source using one or more phosphors.
    Type: Application
    Filed: August 30, 2013
    Publication date: August 13, 2015
    Applicant: The Regents of the University of California
    Inventors: Ram Seshadri, Steven P. DenBaars, Kristin A. Denault, Michael Cantore
  • (In,Ga,Al)N optoelectronic devices grown on relaxed (In,Ga,Al)N-on-GaN base layers
    Patent number: 9076927
    Abstract: A method of fabricating a heterostructure device, including (a) obtaining a first layer or substrate; (b) growing a second layer on the first layer or substrate; and (c) forming the second layer that is at least partially relaxed wherein (1) the first layer and the second layer have the same lattice structure but different lattice constants, (2) the first layer and the second layer form a heterojunction, and (3) the heterojunction forms an active area of a device or serves as a pseudo-substrate for the device.
    Type: Grant
    Filed: November 6, 2013
    Date of Patent: July 7, 2015
    Assignee: The Regents of the University of California
    Inventors: Stacia Keller, Carl J. Neufeld, Umesh K. Mishra, Steven P. DenBaars
  • Semi-polar III-nitride optoelectronic devices on M-plane substrates with miscuts less than +/-15 degrees in the C-direction
    Patent number: 9077151
    Abstract: An optoelectronic device grown on a miscut of GaN, wherein the miscut comprises a semi-polar GaN crystal plane (of the GaN) miscut x degrees from an m-plane of the GaN and in a c-direction of the GaN, where ?15<x<?1 and 1<x<15 degrees.
    Type: Grant
    Filed: March 4, 2011
    Date of Patent: July 7, 2015
    Assignee: The Regents of the University of California
    Inventors: Po Shan Hsu, Kathryn M. Kelchner, Robert M. Farrell, Daniel A. Haeger, Hiroaki Ohta, Anurag Tyagi, Shuji Nakamura, Steven P. DenBaars, S. James Speck
  • (Al,Ga,In)N diode laser fabricated at reduced temperature
    Patent number: 9054498
    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: Grant
    Filed: June 18, 2014
    Date of Patent: June 9, 2015
    Assignee: The Regents of the University of California
    Inventors: Daniel A. Cohen, Steven P. DenBaars, Shuji Nakamura
  • High light extraction efficiency nitride based light emitting diode by surface roughening
    Patent number: 9040326
    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: Grant
    Filed: August 11, 2014
    Date of Patent: May 26, 2015
    Assignee: The Regents of the University of California
    Inventors: Hong Zhong, Anurag Tyagi, Kenneth J. Vampola, James S. Speck, Steven P. DenBaars, Shuji Nakamura
  • Al(x)Ga(1-x)N-cladding-free nonpolar III-nitride based laser diodes and light emitting diodes
    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
  • (Al, In, Ga, B)N DEVICE STRUCTURES ON A PATTERNED SUBSTRATE
    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
  • TUNABLE WHITE LIGHT BASED ON POLARIZATION SENSITIVE LIGHT-EMITTING DIODES
    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
  • METHOD FOR THE REUSE OF GALLIUM NITRIDE EPITAXIAL SUBSTRATES
    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
  • Metalorganic chemical vapor deposition (MOCVD) growth of high performance non-polar III-nitride optical devices
    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
  • LASER-DRIVEN WHITE LIGHTING SYSTEM FOR HIGH-BRIGHTNESS APPLICATIONS
    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
  • TEXTURED PHOSPHOR CONVERSION LAYER LIGHT EMITTING DIODE
    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
  • ANISOTROPIC STRAIN CONTROL IN SEMIPOLAR NITRIDE QUANTUM WELLS BY PARTIALLY OR FULLY RELAXED ALUMINUM INDIUM GALLIUM NITRIDE LAYERS WITH MISFIT DISLOCATIONS
    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