Efficient Circularly Polarized Electroluminescence Enabled by Low-Dimensional Bichiral Perovskite Nanocrystals
Zejian Li, Jiaqi Wang, Shurui Chi, Kebin Lin, Wenchao Zhang, Chenlu He
Abstract
Chiral organic–inorganic hybrid perovskite nanocrystals have gained attention as promising materials for circularly polarized luminescence emission, owing to their high photoluminescence efficiency and superior charge-carrier mobility. However, achieving circularly polarized electroluminescence (CPEL) from mixed-phase perovskite nanocrystals remains a significant challenge. We present bichiral formamidinium lead bromide (FAPbBr 3 ) nanocrystals that achieve room-temperature circularly polarized light-emitting diodes (LEDs) via a synergistic effect between a chiral interior spacer (methylbenzylamine cation, MBA + ) and a chiral surface ligand (camphorsulfonic acid, CSA). The incorporation of MBA + induces chiral crystal lattices, while CSA ligands, featuring sulfonate groups, effectively passivate defects, suppress exciton spin-flip, and enhance conductivity. The resulting circularly polarized LEDs exhibit an enhanced electroluminescence asymmetry factor ( g EL ) of ∼2 × 10 –3, along with an external quantum efficiency (EQE) of 3.1%. These bichiral nanocrystals represent a significant advancement in luminescence efficiency and enantioselectivity, indicating their potential for next-generation chiroptoelectronic applications.