Loading...
News Article

Novel substrate boosts AlGaN UV LED efficiency

News

Patterned sapphire with silica array improves crystal quality and light extraction efficiency

The efficiency of InGaN/AlGaN UV LEDs can be significantly boosted by using a novel substrate, patterned sapphire with silica array (PSSA), according to an international team of researchers.

“The conventional patterned sapphire substrate (PSS) is facing bottlenecks toward achieving higher efficiency AlGaN-based UV LEDs,” said Shengjun Zhou, a professor at Wuhan University, who directed the research. “Our novel substrate provides an unprecedented opportunity in achieving higher electroluminescence performance in future solid-state UV light sources.”

For AlGaN-based UV LEDs grown on conventional PSS, experimental results suggest that the larger sticking coefficient of Al adatoms (than Ga adatoms with sapphire) induces misoriented growth of AlGaN on the sidewall of sapphire patterns and that the limited refractive index contrast between AlGaN and sapphire impedes the outcoupling ability of sapphire patterns. For these reasons, the state-of-the-art UV LEDs still suffer from poor crystal quality and low light extraction efficiency.

The researchers have achieved improved crystal quality and light extraction efficiency by using PSSA, which replaces the sapphire patterns with silica arrays. In comparison to PSS, PSSA reduced the threading dislocation density in AlGaN epilayer, attributing to the preferable vertical growth mode and reduced misfit at the coalescence boundary. Furthermore, PSSA serves as better reflector and refractor than PSS in redirecting light into the escape cone at top and bottom facets owing to the higher-index-contrast given by patterned silica array.

Benefiting from the reduced threading dislocation density and enhanced light extraction efficiency by using PSSA, the efficiency of InGaN/AlGaN UV LEDs has been significantly boosted.

'Boosted ultraviolet electroluminescence of InGaN/AlGaN quantum structures grown on high-index contrast patterned sapphire with silica array'; Nano Energy 69 (2020) 104427

SiC MOSFETs: Understanding the benefits of plasma nitridation
Wolfspeed reports Q2 results
VueReal secures $40.5m to scale MicroSolid printing
Mitsubishi joins Horizon Europe's FLAGCHIP project
Vishay launches new high voltage SiC diodes
UK team leads diamond-FET breakthrough
GaN adoption at tipping point, says Infineon
BluGlass files tuneable GaN laser patents
QD company Quantum Science expands into new facility
Innoscience files lawsuit against Infineon
Riber revenues up 5% to €41.2m
Forvia Hella to use CoolSiC for next generation charging
Photon Design to exhibit QD simulation tool
Ortel transfers CW laser fabrication to Canada
Luminus adds red and blue multi-mode Lasers
PseudolithIC raises $6M for heterogeneous chiplet tech
Mesa sidewall design improves HV DUV LEDs
IQE revenue to exceed expectations
'Game-changing' VCSEL system targets clinical imaging
German start-up secures finance for SiC processing tech
Macom signs preliminaries for CHIPS Act funding
IQE and Quintessent partner on QD lasers for AI
EU funds perovskite tandems for fuel-free space propulsion
EU to invest €3m in GeSi quantum project
Transforming the current density of AlN Schottky barrier diodes
Turbocharging the GaN MOSFET with a HfO₂ gate
Wolfspeed launches Gen 4 SiC MOSFET technology
Report predicts high growth for UK's North East
Element Six unveils Cu-diamond composite
SemiQ launches hi-rel 1700V SiC MOSFETs
Lynred to exhibit Eyesential SWIR sensor for machine vision
Thorlabs buys VCSEL firm Praevium Research
×
Search the news archive

To close this popup you can press escape or click the close icon.
Logo
x
Logo
×
Register - Step 1

You may choose to subscribe to the Compound Semiconductor Magazine, the Compound Semiconductor Newsletter, or both. You may also request additional information if required, before submitting your application.


Please subscribe me to:

 

You chose the industry type of "Other"

Please enter the industry that you work in:
Please enter the industry that you work in: