Degradation Mechanisms in Quantum-Dot Light-Emitting Diodes: A Perspective on Nondestructive Analysis

Quantum-dot light-emitting diodes (QLEDs) have emerged as promising candidates for next-generation display technologies owing to their high color purity and external quantum efficiency. Despite rapid advancements in device performance, operational stability and long-term reliability remain critical challenges, particularly for cadmium-free and blue-emitting QLEDs. This review provides a comprehensive overview of the degradation mechanisms of QLEDs, emphasizing the relationship between environmental factors, such as moisture, oxygen, and thermal stress, and excitonic factors, including charge-injection imbalance, Auger recombination, and interface deterioration. We further highlight the role of nondestructive characterization techniques, including impedance spectroscopy, Fourier transform infrared spectroscopy, transient photoluminescence, transient electroluminescence, transient absorption, and electroabsorption spectroscopy, in probing real-time charge dynamics and material degradation. By integrating the insights from these operando analyses, this review offers a detailed perspective on the origins of device degradation and provides guidance for rational design strategies aimed at enhancing the operational stability and commercialization potential of QLEDs.