In-Situ Surface\nRepair of FAPbBr<sub>3</sub> Quantum\nDots toward High-Performance Pure-Green Perovskite Light-Emitting\nDiodes

Metal\nhalide perovskite light-emitting diodes (PeLEDs) are ideal\nfor high-resolution displays due to their tunable emission, narrow\nspectra, and low-cost processing. Colloidal FAPbBr<sub>3</sub> perovskite\nquantum dots (PeQDs) enhance radiative recombination, making them\nefficient for pure-green PeLEDs. However, their low stability and\nsurface defects limit their practical application. Here, we address\nthese challenges by proposing an in situ surface repair strategy using\nbenzhydroxamic acid (BHA) as a modifier. We demonstrated that BHA\ncan coordinate with Pb<sup>2+</sup> ions and form hydrogen bonds with\nFA<sup>+</sup> and halide ions, effectively reducing nonradiative\nrecombination and maintaining the integrity of the PeQDs. High-quality\nFAPbBr<sub>3</sub> PeQDs with a photoluminescence quantum yield (PLQY)\nof up to 92.5% were achieved, leading to pure-green PeLEDs with an\nexternal quantum efficiency (EQE) of 24.8% and a maximum luminance\nof 40,231 cd m<sup>–2</sup>, providing a feasible and promising\nperspective for advanced solid-state lighting and displays.