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High-Efficiency, Mirrorless Non-Polar and Semi-Polar Light Emitting Devices

Technology Benefits

More effective generation of polarized light than c-plane devicesHigher efficiency LEDsReduced internal reflections within the LED

Technology Application

LEDs and LDs

Detailed Technology Description

Researchers at UC Santa Barbara have developed an (Al, Ga, In)N light emitting device in which high light generation efficiency occurs by fabricating the device using non-polar or semi-polar GaN crystals. This geometry allows for a QW layer larger than 5 nm with low piezoelectric effects so that higher efficiencies at higher current densities can be achieved. The device also minimizes internal reflections within the LED by eliminating mirrors and/or mirrored surfaces, in order to minimize re-absorption of light by the emitting or active layer of the LED.

Application No.

9130119

Others

Background

The thickness of the quantum well (QW) in conventional GaN-based LEDs and LDs is only around 2-5 nm, due to the c-axis oriented GaN crystals which limit the thickness of the QW that can be achieved without losing efficiency. Conventional LEDs also utilize mirrors to increase the light output power from the front side of the LED. Reflected emissions are partially re-absorbed by the LED, further reducing the output power and efficiency of the LED.

Additional Technologies by these Inventors

• Reduced Dislocation Density of Non-Polar GaN Grown by Hydride Vapor Phase Epitaxy
• Growth of Planar, Non-Polar, A-Plane GaN by Hydride Vapor Phase Epitaxy
• Nonpolar (Al, B, In, Ga)N Quantum Well Design
• Improved Manufacturing of Semiconductor Lasers
• Cleaved Facet Edge-Emitting Laser Diodes Grown on Semipolar GaN
• Etching Technique for the Fabrication of Thin (Al, In, Ga)N Layers
• Enhancing Growth of Semipolar (Al,In,Ga,B)N Films via MOCVD
• GaN-Based Thermoelectric Device for Micro-Power Generation
• Growth of High-Quality, Thick, Non-Polar M-Plane GaN Films
• Method for Growing High-Quality Group III-Nitride Crystals
• Growth of Planar Semi-Polar Gallium Nitride
• Defect Reduction of Non-Polar and Semi-Polar III-Nitrides
• MOCVD Growth of Planar Non-Polar M-Plane Gallium Nitride
• Lateral Growth Method for Defect Reduction of Semipolar Nitride Films
• Low Temperature Deposition of Magnesium Doped Nitride Films
• Growth of Polyhedron-Shaped Gallium Nitride Bulk Crystals
• Improved Manufacturing of Solid State Lasers via Patterning of Photonic Crystals
• Control of Photoelectrochemical (PEC) Etching by Modification of the Local Electrochemical Potential of the Semiconductor Structure
• Phosphor-Free White Light Source
• Single or Multi-Color High Efficiency LED by Growth Over a Patterned Substrate
• High Efficiency LED with Optimized Photonic Crystal Extractor
• Packaging Technique for the Fabrication of Polarized Light Emitting Diodes
• LED Device Structures with Minimized Light Re-Absorption
• (In,Ga,Al)N Optoelectronic Devices with Thicker Active Layers for Improved Performance
• Oxyfluoride Phosphors for Use in White Light LEDs
• III-V Nitride Device Structures on Patterned Substrates
• Growth of Semipolar III-V Nitride Films with Lower Defect Density
• Improved GaN Substrates Prepared with Ammonothermal Growth
• Enhanced Optical Polarization of Nitride LEDs by Increased Indium Incorporation
• Semipolar-Based Yellow, Green, Blue LEDs with Improved Performance
• Hexagonal Wurtzite Type Epitaxial Layer with a Low Alkali-Metal Concentration
• Photoelectrochemical Etching Of P-Type Semiconductor Heterostructures
• Photoelectrochemical Etching for Chip Shaping Of LEDs
• Highly Efficient Blue-Violet III-Nitride Semipolar Laser Diodes
• Method for Manufacturing Improved III-Nitride LEDs and Laser Diodes: Monolithic Integration of Optically Pumped and Electrically Injected III-Nitride LEDs
• Defect Reduction in GaN films using in-situ SiNx Nanomask
• Semi-polar LED/LD Devices on Relaxed Template with Misfit Dislocation at Hetero-interface
• Limiting Strain-Relaxation in III-Nitride Heterostructures by Substrate Patterning
• Suppression of Defect Formation and Increase in Critical Thickness by Silicon Doping
• High Efficiency Semipolar AlGaN-Cladding-Free Laser Diodes
• Low-Cost Zinc Oxide for High-Power-Output, GaN-Based LEDs (UC Case 2010-183)
• Low-Cost Zinc Oxide for High-Power-Output, GaN-Based LEDs (UC Case 2010-150)
• Nonpolar III-Nitride LEDs With Long Wavelength Emission
• Method for Growing Self-Assembled Quantum Dot Lattices
• Method for Increasing GaN Substrate Area in Nitride Devices
• Flexible Arrays of MicroLEDs using the Photoelectrochemical (PEC) Liftoff Technique
• Optimization of Laser Bar Orientation for Nonpolar Laser Diodes
• UV Optoelectronic Devices Based on Nonpolar and Semi-polar AlInN and AlInGaN Alloys
• Low-Droop LED Structure on GaN Semi-polar Substrates
• Improved Fabrication of Nonpolar InGaN Thin Films, Heterostructures, and Devices
• Growth of High-Performance M-plane GaN Optical Devices
• Method for Enhancing Growth of Semipolar Nitride Devices
• Transparent Mirrorless (TML) LEDs
• Solid Solution Phosphors for Use in Solid State White Lighting Applications
• Technique for the Nitride Growth of Semipolar Thin Films, Heterostructures, and Semiconductor Devices
• Planar, Nonpolar M-Plane III-Nitride Films Grown on Miscut Substrates
• High Light Extraction Efficiency III-Nitride LED
• Tunable White Light Based on Polarization-Sensitive LEDs
• Method for Improved Surface of (Ga,Al,In,B)N Films on Nonpolar or Semipolar Subtrates
• Improved Anisotropic Strain Control in Semipolar Nitride Devices
• III-Nitride Tunnel Junction with Modified Interface
• Enhanced Light Extraction LED with a Tunnel Junction Contact Wafer Bonded to a Conductive Oxide
• Increased Light Extraction with Multistep Deposition of ZnO on GaN
• Hybrid Growth Method for Improved III-Nitride Tunnel Junction Devices
• Calcium Impurity Reduction for Improved Light-Emitting Devices
• Contact Architectures for Tunnel Junction Devices
• New Blue Phosphor for High Heat Applications
• Internal Heating for Ammonothermal Growth of Group-III Nitride Crystals
• Methods for Fabricating III-Nitride Tunnel Junction Devices
• Multifaceted III-Nitride Surface-Emitting Laser
• Laser Diode System For Horticultural Lighting
• Fabricating Nitride Layers
• Reduction in Leakage Current and Increase in Efficiency of III-Nitride MicroLEDS
• Vertical Cavity Surface-Emitting Lasers with Continuous Wave Operation
• Laser Lighting System Incorporating an Additional Scattered Laser

Tech ID/UC Case

25552/2007-317-0

Related Cases

2007-317-0

*Abstract

An (Al, Ga, In)N light emitting device in which high light generation efficiency occurs by fabricating the device using non-polar or semi-polar GaN crystals.

*IP Issue Date

Sep 8, 2015

*Principal Investigator

Name: Steven DenBaars

Department:

Name: Kwang Choong Kim

Department:

Name: Shuji Nakamura

Department:

Name: Mathew Schmidt

Department:

Name: James Speck

Department:

Country/Region

USA