Carrier Dynamics in Quantum Dot Light‐Emitting Diodes: The Conversion between Electrons, Excitons, and Photons

Abstract Electrically driven self‐emissive quantum dot light‐emitting diodes (QLEDs) offer the advantages of high contrast, high color saturation and simple solution processability, making them the ultimate target for commercialization of QD‐based displays. Challenges remain, such as the lack of a comprehensive understanding of device mechanisms, the poor performance of blue Cd‐based and Cd‐free devices, and the immature of color patterning processes, which are far from the requirements of practical applications. The study of carrier dynamics is a crucial part of understanding the physical mechanisms of devices and improving their performance. Therefore, this review summarizes and discusses the related researches on the conversion process between electrons, excitons and photons in QLEDs. First, an overview of the electron‐photon conversion process is given to elucidate the underlying principles of QLEDs. Then, the two sub‐processes involved, the exciton formation process and the photon formation process, are discussed. Next, the most commonly used characterization tools for the study of carrier dynamics are presented. Finally, the opportunities and challenges associated with QLED research on carrier dynamics are summarized and outlined.