Angle-tuned, evanescently-decoupled reflector for high-efficiency red light-emitting diode.

Area of Science:

• Optoelectronics
• Materials Science

Background:

• AlGaInP light-emitting diodes (LEDs) are crucial for various lighting applications.
• Enhancing light extraction efficiency in LEDs remains a key challenge.

Purpose of the Study:

• To propose and demonstrate novel distributed Bragg reflectors (DBRs) for AlGaInP LEDs.
• To optimize DBR design for improved light output power and horizontal radiation.

Main Methods:

• Designed evanescently-decoupled, solid-angle-optimized DBRs.
• Tuned DBR layer thickness and employed thicker AlAs layers for enhanced reflectivity.
• Incorporated a square-lattice hole array on the top GaP surface.

Main Results:

• Achieved a 1.9-fold enhancement in integrated output power with improved DBRs compared to conventional ones.
• Observed an additional 1.25-fold enhancement by integrating a square-lattice hole array.
• Demonstrated increased horizontal radiation through side facets.

Conclusions:

• Evanescently-decoupled, solid-angle-optimized DBRs significantly improve AlGaInP LED performance.
• Surface texturing further enhances light extraction efficiency.
• The developed DBRs offer a promising approach for high-efficiency LED design.