Highly efficient AlGaN-based deep-ultraviolet light-emitting diodes: from bandgap engineering to device craft
Xu Liu1, Zhenxing Lv1, Zhefu Liao1
1Center for Photonics and Semiconductors, School of Power and Mechanical Engineering, Wuhan University, Wuhan, 430072 China.
Microsystems & Nanoengineering
|August 15, 2024
Summary
Researchers developed advanced deep-ultraviolet (DUV) light-emitting diodes (LEDs) using AlGaN material. These LEDs achieve significantly improved external quantum efficiency (EQE) for sterilization applications.
Area of Science:
- Materials Science
- Optoelectronics
- Semiconductor Physics
Background:
- Deep-ultraviolet (DUV) light-emitting diodes (LEDs) based on aluminum gallium nitride (AlGaN) are crucial for physical sterilization.
- Poor external quantum efficiency (EQE) in conventional AlGaN-based DUV LEDs limits their performance and widespread adoption.
Purpose of the Study:
- To enhance the performance of 270-nm AlGaN-based DUV LEDs beyond the current state-of-the-art.
- To overcome key challenges including quantum-confined Stark effect (QCSE), optical absorption, and poor light extraction.
Main Methods:
- Implementation of tailored multiple quantum wells (MQWs) for bandgap engineering.
- Integration of a reflective aluminum (Al) reflector.
- Utilization of a low-optical-loss tunneling junction (TJ) and a dielectric SiO2 insertion structure (IS-SiO2).
Main Results:
- Achieved outstanding light output powers (LOPs) of 140.1 mW at 850 mA.
- Demonstrated a 4.5-fold increase in EQEs compared to conventional DUV LEDs.
- Validated scalability for larger production scales through on-wafer electroluminescence characterization.
Conclusions:
- The developed comprehensive approach effectively addresses major limitations in high-performance AlGaN-based DUV LED fabrication.
- The results show significant promise for the development of highly efficient DUV LEDs for sterilization and other applications.
