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

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 T₉₅ 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.