Overcoming Exciton Quenching at the ZnMgO/InP Quantum Dot Interface for Stable LEDs

ABSTRACT Cadmium‐free indium phosphide (InP) quantum dots (QDs) are promising emitters for environmentally benign next‐generation light‐emitting diodes (LEDs), yet their application is hindered by poor operational stability. This limitation arises from electron trapping and exciton quenching at the InP/ZnMgO interface, where delocalized electrons from InP QDs are readily captured by oxygen vacancies (O V ) in ZnMgO. Here, we demonstrate highly stable InP‐based QD‐LEDs by rationally passivating ZnMgO with organic fluoride ions (F − ). The strong binding affinity of F − effectively passivates O V sites and suppresses ion migration under electrical injections, thereby lowering defect density and mitigating nonradiative recombination at the interface. As a result, we achieve red InP QD‐LEDs with a peak external quantum efficiency (EQE) of 25.35% and a maximum luminance of 137 464 cd m −2 . Remarkably, the T 95 operational lifetime at 1000 cd m −2 extends to 1504 h. Furthermore, InP QDs exhibit excellent compatibility with the micro‐LED configuration, maintaining an EQE of 23.29% at a micropixel size of 2 µm. These results highlight a viable pathway toward efficient, stable, and environmentally benign InP‐based micro‐LEDs for next‐generation near‐eye displays.