High external quantum efficiency (6.8%) UV-A LEDs on AlN templates with quantum barrier optimization

Area of Science:

• Semiconductor Physics
• Optoelectronics
• Materials Science

Background:

• Aluminum Gallium Nitride (AlGaN)-based Ultraviolet A (UV-A) Light Emitting Diodes (LEDs) are crucial for medical treatments and chemical sensing.
• Current UV-A LED efficiencies lag behind visible and UV-C counterparts due to lattice mismatch issues between the active region and AlN substrate.

Purpose of the Study:

• To investigate the impact of quantum barrier composition and thickness on the performance of AlGaN-based UV-A LEDs.
• To enhance strain management and carrier confinement within the LED active region.

Main Methods:

• Fabrication of AlGaN-based UV-A LEDs with varying quantum barrier parameters.
• Characterization of LED performance, including efficiency and wavelength output.
• Analysis of strain distribution and carrier dynamics.

Main Results:

• Optimized quantum barrier design led to improved strain management and enhanced carrier confinement.
• Demonstrated efficient UV-A LEDs emitting between 320 nm and 330 nm.
• Achieved External Quantum Efficiencies (EQEs) up to 6.8%, representing a significant improvement for this wavelength range.

Conclusions:

• The composition and thickness of quantum barriers are critical factors for improving UV-A LED performance.
• The developed LED structures show promising results for high-efficiency UV-A light generation.
• This work contributes to advancing UV-A LED technology for various applications.