Manipulating Structural Asymmetry in FAPbBr ₃ Quantum Dots for High-Performance Pure-Green Spin-Polarized Light-Emitting Diodes

Spin-polarized light-emitting diodes (spin-LEDs) hold promise for next-generation photonic technologies owing to their ability to directly emit circularly polarized electroluminescence. Here, we report a multifunctional chiral ligand engineering strategy to realize high-performance pure-green spin-LEDs based on FAPbBr 3 quantum dots (QDs). By introducing ( R/S )-methylbenzenesulfinamide, strong coordination with surface Pb 2+ ions simultaneously passivates defects and induces pronounced centrosymmetry-breaking lattice distortion in FAPbBr 3 QDs. This structural asymmetry enhances chiroptical activity and prolongs spin-coherence lifetimes, enabling efficient spin-polarized carrier recombination. As a result, chiral FAPbBr 3 QDs exhibit a high photoluminescence quantum yield (98.28%) and large dissymmetry factor (8.87 × 10 –2 ). The spin-LEDs fabricated from these QDs exhibit pure-green emission, with a maximum luminance of 17 979 cd m –2, a peak external quantum efficiency of 15.1%, and a maximum electroluminescence dissymmetry factor of 1.76 × 10 –1 at room temperature. This work demonstrates that chiral MBS ligands can simultaneously improve optoelectronic quality and introduce structural asymmetry in perovskite quantum dots, representing a promising route toward practical high-performance spin-LEDs.