Ultrafast Gated Hyperspectral Imaging System for Spatial-Spectral-Temporal-Resolved Electroluminescence of Miniaturized Light-Emitting Diodes

Miniaturized light-emitting diodes (Mini-/Micro-LEDs) for next-generation displays exhibit complex optoelectronic behaviors due to the shrunk chip size. Comprehensive multi-dimensional characterization is critical yet remains challenging for conventional techniques. In this work, we proposed an ultrafast gated hyperspectral imaging (UGHSI) system that synchronously captures spatial, spectral, and temporal dynamics in miniaturized LEDs, addressing the growing demand for high-resolution, multi-dimensional analysis of their complex transient behaviors. High-resolution two-dimensional (2-D) time-resolved electroluminescence (TREL) measurements are applied to demonstrate the system’s sub-micron spatial resolution and 500 picosecond temporal resolution. To enhance measurement accuracy, an optimized fitting model is developed to compensate the impact of the falling time of the electrical pulse signal on fluorescence lifetime. The 2-D fluorescent lifetime mappings for green Mini/Micro-LEDs derived from the 2-D TREL reveal distinct carrier distribution patterns and luminescence behaviors. In particular, the lifetime mappings clarify the enhanced anomalous emission at the sidewalls of the Mini/Micro-LEDs. In general, the proposed system achieves multi-dimensional optoelectronic characteristics with improved resolution and flexibility, providing a cutting-edge tool for studying complex behaviors of the next-generation devices and materials at microscopic and picosecond scales.