Blue Quantum‐Dot Light‐Emitting Diodes for High‐Luminance Displays: Fundamental Challenges and Emerging Strategies

ABSTRACT

The growing demand for outdoor, automotive, virtual reality (VR), and augmented reality (AR) displays has stimulated extensive research into light sources capable of high‐luminance operation. Among emerging display technologies, quantum‐dot light‐emitting diodes (QLEDs) are particularly attractive because of their high color purity, widely tunable emission, high efficiency, and compatibility with solution‐based fabrication and patterning. However, the realization of stable high‐luminance full‐color QLED displays remains limited primarily by the inferior performance of blue devices. The wide bandgap and deep valence‐band levels of blue quantum dots (QDs) hinder hole injection and induce severe charge imbalance, while operation at elevated luminance intensifies Joule heating, charge accumulation, multicarrier Auger recombination, and degradation of the emitting QDs and adjacent transport layers. These coupled thermal and electrical effects result in pronounced efficiency roll‐off and rapid lifetime deterioration. In this review, we examine the fundamental limitations of high‐luminance blue QLEDs and summarize recent strategies based on thermal management, charge balance enhancement, and leakage suppression. Furthermore, we discuss the remaining challenges in high‐luminance lifetime evaluation, efficiency retention, and device integration to provide perspectives for realizing bright and stable blue QLEDs in next‐generation displays.