+44 (0)24 7671 8970
More publications     •     Advertise with us     •     Contact us
 
Loading...
News Article

Bandgap-engineering increases wavelength and output power

News

WHU team reports simultaneous increase in emission wavelength and light output power in yellow LEDs

Researchers from Wuhan University in China have reported the achievement of simultaneous increase in emission wavelength and light output power of yellow LEDs based on staggered quantum wells.

“We observe unexpected optoelectronic properties in LEDs with staggered quantum well grown under different TMIn flux. Based on the experimental data, the strain-induced composition pulling effect is alleviated in staggered QWs grown under low TMIn flux, which enables more indium incorporation in the following high-indium-composition layer. Our study provides new insights into designing epitaxial structures, which facilitates InGaN-based LEDs towards highly efficient and long-wavelength emission prospects,” said Shengjun Zhou, a professor at Wuhan University who directed the research.

Although blue LEDs achieving a high external quantum efficiency, the emission efficiency is limited in the long wavelength region, which is commonly known as 'green-yellow gap' phenomenon. With the increasing emission wavelength, the efficiency of long wavelength InGaN-based LED decreases dramatically.

The researchers investigate the effect of TMIn flux variation for growing bandgap-engineered staggered quantum wells on corresponding LED properties. At 20 mA, LEDs based on staggered QWs grown under low flux show an increase of 28 percent in light output power (LOP) and longer wavelength compared to that under high flux.

Under high TMIn flux, high in-plane strain exists between adjacent layers, accompanied by the composition pulling effect, which reduces indium incorporation for the following staggered QW growth and hinders realization of yellow light emission.

According to simulation results, low-flux-grown staggered QWs contribute to increased carrier wavefunction overlap as well as enhanced electric field. The former enables high LOP, while the latter results in the emission towards long wavelength, promising to solve an ever-present concern that InGaN-based long wavelength LED performance deteriorates with increasing emission wavelength.

'Unexpectedly Simultaneous Increase in Wavelength and Output Power of Yellow LEDs Based on Staggered Quantum Wells by TMIn Flux Modulation'; Nanomaterials 2022, 12, 3378.

CS International champions a green agenda
Wolfspeed selects Aixtron tools to support 200 mm production
Aixtron wins the prestigious German Innovation Award
Infineon provides Fox ESS with power semiconductors
TriEye and Vertilas demonstrate 1.3 μm VCSEL-driven SWIR sensing solutions
Polychromatic pixels
Infineon receives “GaN Strategic Partner of the Year” award
SweGaN announces strategic partnership with RFHIC
Q-Pixel debuts the world’s highest resolution (6800 PPI) color display
Aixtron receives Gold Supplier award
Coherent secures $15M CHIPS funding through CLAWS Hub
UK CSA Catapult celebrates success
Transforming displays with photo-responsive PeLEDs
US team reinvents the photoconductive switch
Filtronic enhances packaging capabilities
IQE posts full year 2023 results
CSA Catapult opens DER-funded packaging facility
What’s next for SiC?
Power electronics market to reach $69.7B by 2030
EPC announces GaN FET-based audio amp
Arizona State University to explore potential of AlN
Teledyne e2v HiRel announces GaN load switch
Aehr wins major order for SiC wafer test and burn-in system
Innoscience releases GaN driver IC
POET and MultiLane collaborate
III-V Epi reports a year of growth
VECSELS are a step towards the quantum Internet
Navitas to focus on grid reliability at PE International
SiC Innovation Alliance to drive industrial-scale R&D
Axcelis SiC ion implanters see success in Japan
Far-UVC kills 99% of airborne viruses in occupied room
SemiQ expands with new Taiwan office
×
Search the news archive

To close this popup you can press escape or click the close icon.
×
  • 1st January 1970
  • 1st January 1970
  • 1st January 1970
  • 1st January 1970
  • 1st January 1970
  • 1st January 1970
  • 1st January 1970
  • 1st January 1970
  • View all news
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: