Investigation on the electroluminescence 2D microscopic localization intensity distribution of GaN-based flip-chip green mini-LEDs

Abstract

Based on time-gated electroluminescence, a method to characterize the localized intensity distribution (LID) of flip-chip green mini-LEDs is proposed. Through the integration of RC circuit theory and carrier dynamics, the underlying physical mechanism of the double-exponential model is elucidated. Subsequent to analyzing the light emission behavior of LEDs during rising and falling edge phases, microscopic localized intensity is innovatively quantified and assessed via multi-metric joint analysis. The LID metrics align with radiative recombination efficiency, especially in the mesa region, validating its consistency with fundamental physical principles. Data reveal relatively high LID in the central mesa between the anode and the cathode, moderate LID in partial sidewalls, and low LID near the cathode and most sidewall regions. Correlating these microscopic features with process parameters offers insights for passivation optimization, homogeneous current injection, and low-damage etching, providing a 2D analytical framework to boost the performance and enhance the reliability of mini-LEDs.