In-Situ Surface Repair of FAPbBr₃ Quantum Dots toward High-Performance Pure-Green Perovskite Light-Emitting Diodes

Metal halide perovskite light-emitting diodes (PeLEDs) are ideal for high-resolution displays due to their tunable emission, narrow spectra, and low-cost processing. Colloidal FAPbBr₃ perovskite quantum dots (PeQDs) enhance radiative recombination, making them efficient for pure-green PeLEDs. However, their low stability and surface defects limit their practical application. Here, we address these challenges by proposing an in situ surface repair strategy using benzhydroxamic acid (BHA) as a modifier. We demonstrated that BHA can coordinate with Pb²⁺ ions and form hydrogen bonds with FA⁺ and halide ions, effectively reducing nonradiative recombination and maintaining the integrity of the PeQDs. High-quality FAPbBr₃ PeQDs with a photoluminescence quantum yield (PLQY) of up to 92.5% were achieved, leading to pure-green PeLEDs with an external quantum efficiency (EQE) of 24.8% and a maximum luminance of 40,231 cd m^-2, providing a feasible and promising perspective for advanced solid-state lighting and displays.