Growth and characterization of micro-LED based on GaN substrate

Area of Science:

• Materials Science
• Solid State Physics
• Optoelectronics

Background:

• Advancements in micro-light-emitting diode (micro-LED) technology are increasingly dependent on understanding dislocation phenomena.
• Gallium nitride (GaN)-based micro-LEDs are crucial for next-generation displays and lighting.

Purpose of the Study:

• To investigate the influence of epitaxial configuration on GaN-based micro-LED performance.
• To elucidate the mechanisms behind V-shaped pit formation and their impact on device uniformity and efficiency.

Main Methods:

• Comparative analysis of homoepitaxial and heteroepitaxial GaN micro-LED structures.
• Characterization of dislocation density, residual stress, and V-shaped pit distribution.
• Optimization of homoepitaxial structures to enhance external quantum efficiency (EQE).

Main Results:

• Homoepitaxial micro-LEDs exhibit significantly lower dislocation density and residual stress, preventing V-shaped pit formation and ensuring superior uniformity.
• Homoepitaxial micro-LEDs achieved a 40% higher peak external quantum efficiency (EQE) compared to heteroepitaxial counterparts.
• Optimization of the homoepitaxial structure, leveraging reduced multi-quantum well (MQW) thickness at V-shaped pit sidewalls, enhanced EQE from 7.9% to 14.8% (@ 10 A/cm²).

Conclusions:

• Reducing dislocation density and residual stress through homoepitaxy is critical for high-uniformity micro-LEDs.
• Optimized homoepitaxial structures with low-energy-barrier MQWs significantly improve micro-LED performance, leading to high brightness and low power consumption.
• Homoepitaxial growth offers a promising pathway for advancing micro-LED technology towards superior uniformity and efficiency.