Spatial-Spectral-Temporal Dynamic Investigation during Carrier Injection in Mini-Light-Emitting Diodes

Time-resolved electroluminescence (TREL) during the carrier injection in mini-light-emitting diodes (mini-LEDs) directly reflects the dynamic evolution of carrier recombination mechanisms. However, it is still a challenge to simultaneously acquire spatial, spectral and temporal information and to enable quantitative analysis of recombination dynamics. In this work, a self-developed ultrafast gated hyperspectral imaging (UGHSI) system is employed to obtain multidimensional TREL data during the rising-edge injection process, enabling combined spatial-spectral-temporal characterization of emission. A modified time-dependent ABC model is introduced to quantitatively investigate recombination dynamics during carrier injection, revealing the dynamic competition between radiative and nonradiative recombination and their spatial evolution. Results show pronounced spatial nonuniformity during emission establishment. The emission in the mesa region evolves from earlier Shockley–Read–Hall (SRH)-dominated recombination to radiative recombination, while the sidewall region remains dominated by SRH recombination for a longer period due to higher defect density. Auger recombination emerges preferentially in high-injection regions, reflecting the injection-dependent competition among SRH, radiative, and Auger recombination. This work establishes a multidimensional quantitative analysis method for the rising-edge injection process, providing a new experimental approach for understanding structure-dependent recombination dynamics in micro/mini-LEDs and offering physical insights for device structure optimization and sidewall defect passivation improvement.