Stepwise gradient etching for low-defect GaN Micro-LEDs with suppressed non-radiative recombination.

Area of Science:

• Materials Science
• Optoelectronics
• Semiconductor Device Physics

Background:

• Micro-light-emitting diode (Micro-LED) technology is crucial for next-generation displays.
• Device miniaturization in Micro-LEDs leads to efficiency degradation due to sidewall damage.
• Addressing luminescent efficiency loss is vital for Micro-LED advancement.

Purpose of the Study:

• To investigate a stepwise gradient (SWG) etching process for Micro-LED device patterning.
• To analyze the impact of SWG etching on sidewall morphology and uniformity.
• To establish a process-structure-performance relationship for optimized Micro-LEDs.

Main Methods:

• Implementing a stepwise gradient (SWG) etching technique for Micro-LED fabrication.
• Characterizing sidewall morphology and etching uniformity under varied processing conditions.
• Evaluating the effects of SWG etching on SRH non-radiative recombination and leakage currents.

Main Results:

• The SWG etching process effectively suppresses sidewall damage in Micro-LEDs.
• Reduced sidewall damage leads to attenuated non-radiative recombination and leakage currents.
• Enhanced external quantum efficiency is achieved through optimized sidewall properties.
• Stepwise etching parameters influence light emission distribution and photon extraction.

Conclusions:

• The SWG etching process is a viable strategy to mitigate efficiency degradation in miniaturized Micro-LEDs.
• Understanding the process-structure-performance link is critical for high-efficiency Micro-LED design.
• This research provides a pathway for improving Micro-LED performance in intelligent display applications.