Development of blue-light GaN based micro light-emitting diodes using ion implantation technology

Area of Science:

• Materials Science
• Optoelectronics
• Semiconductor Physics

Background:

• Micro-LEDs (μLEDs) are crucial for advanced displays.
• Mesa fabrication is key to μLED performance.
• Dry etching can introduce sidewall defects, impacting device efficiency.

Purpose of the Study:

• To investigate ion implantation as an alternative to dry etching for μLED mesa fabrication.
• To analyze the impact of different ion species (As, Ar) on μLED performance.
• To demonstrate defect reduction strategies for small chip size devices.

Main Methods:

• Fabrication of 10 μm chip size blue GaN-based μLEDs.
• Mesa isolation using dry etching and ion implantation (As, Ar).
• Electrical and optical characterization of fabricated μLEDs.

Main Results:

• Ion-implanted μLEDs showed superior turn-on characteristics and lower leakage current than dry-etched devices.
• Argon-implanted μLEDs exhibited reduced dynamic (R_d) and series resistance (R_s).
• Wall-plug efficiency reached 10.66% and external quantum efficiency (EQE) improved significantly with implantation, especially Ar ions.

Conclusions:

• Reducing mesa sidewall defects via ion implantation enhances μLED properties by suppressing non-radiative recombination.
• Replacing dry etching with ion implantation can decrease the ideality factor and boost EQE in small μLEDs.