A Review of Transient Characterization Techniques for Quantum Dot Light‐Emitting Diodes

ABSTRACT Quantum dot light‐emitting diodes (QLEDs) have emerged as a promising display technology owing to their high color purity, tunable emission, and solution processability. Despite significant progress in device performance, a complete understanding of their operating mechanisms remains elusive. The key processes governing QLED operation, including charge injection, exciton formation, exciton recombination, and device degradation, span broad time scales, which limit the insights obtainable from steady‐state measurements alone. In contrast, transient characterization techniques enable direct interrogation of these dynamic processes under optical or electrical excitation. This review provides a comprehensive overview of transient characterization techniques applied to QLEDs, including time‐resolved photoluminescence, transient electroluminescence, transient absorption, and electrically pumped transient absorption. The measurement principles, experimental configurations, and the specific mechanistic information accessible by each technique are introduced first. Representative studies are then discussed to illustrate how these techniques elucidate carrier injection dynamics, exciton formation and recombination pathways, and degradation mechanisms in operating QLEDs. Finally, current challenges and future opportunities are outlined, emphasizing the critical role of transient characterization techniques in guiding the design of efficient and operationally stable QLEDs.