Media.Player

Semipolar-Based Yellow, Green, Blue LEDs with Improved Performance

Technology Benefits

Growth of thicker quantum wellsReduced polarization fields in the device structureReduced defect formation in the active layerLonger wavelength emission

Technology Application

Green, yellow, and blue GaN based light emitting diodesLaser diodesMulti-junction solar cells

Detailed Technology Description

Researchers at the University of California, Santa Barbara have developed a novel approach to reducing or possibly eliminating the polarization effects in GaN-based optoelectronic devices. This approach includes growing the devices on semipolar planes of the crystal. Using semipolar planes instead of c-plane nitrides will reduce total polarization, and there may even be zero polarization for specific alloy compositions. Reducing the polarization field allows for the growth of thicker quantum wells. With thicker quantum wells, higher Indium composition and thus longer wavelength emission can be achieved. The novel approach allows for the fabrication of blue, green, and yellow LEDs on semipolar (Al, In, Ga, B)N semiconductor crystals.

Supplementary Information

Patent Number: US8148713B2
Application Number: US2009419119A
Inventor: Sato, Hitoshi | Hirasawa, Hirohiko | Chung, Roy B. | DenBaars, Steven P. | Speck, James S. | Nakamura, Shuji
Priority Date: 4 Apr 2008
Priority Number: US8148713B2
Application Date: 6 Apr 2009
Publication Date: 3 Apr 2012
IPC Current: H01L002906 | H01L003302 | H01L003332
US Class: 257013 | 257014 | 257090 | 257E21002 | 257E33002 | 438028 | 977755
Assignee Applicant: The Regents of the University of California
Title: Method for fabrication of semipolar (Al, In, Ga, B)N based light emitting diodes
Usefulness: Method for fabrication of semipolar (Al, In, Ga, B)N based light emitting diodes
Summary: The yellow, amber or red LED is useful in a multi-color LED device, where the semipolar yellow LED is useful in a white LED device (all claimed) and the multi-color LED device is useful in electronic and optoelectronic devices.
Novelty: Yellow, amber or red LED useful in a multi-color LED device, comprises an active layer for emitting light, where the active layer is comprised of indium containing single or multi-quantum well structures

Industry

Electronics

Sub Category

Display

Application No.

8148713

Others

Background

Conventional nitride technology for electronic and optoelectronic devices employs nitride films grown along the polar c-direction. However, conventional structures in III-nitride based optoelectronic and electronic devices suffer from the undesirable quantum-confined Stark effect (QCSE), due to the existence of strong piezoelectric and spontaneous polarizations. One approach to eliminating the polarization effects in devices is to grow the devices on nonpolar planes of the crystal. Unfortunately, growth on nonpolar nitrides remains challenging and has not yet been widely adopted in the III-nitride industry.

 

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

23656/2008-415-0

Related Cases

2008-415-0

*Abstract

A novel approach to reducing or possibly eliminating the polarization effects in GaN-based optoelectronic devices.

 

*IP Issue Date

Apr 3, 2012

*Principal Investigator

Name: Steven DenBaars

Department:

Name: James Speck

Department:

Name: Roy Chung

Department:

Name: Hirohiko Hirawawa

Department:

Name: Shuji Nakamura

Department:

Name: Hitoshi Sato

Department:

Country/Region

USA