Efficient Circularly Polarized Near-Infrared Luminescence from Zero-Dimensional Hybrid Copper Bromides

Circularly polarized luminescence (CPL) provides an additional degree of freedom for light manipulation beyond intensity and wavelength and is essential for advanced photonic technologies. Chiral hybrid metal halides (HMHs) have recently emerged as promising CPL-active materials. However, the simultaneous realization of high efficiency near-infrared (NIR) emission and strong CPL remains challenging. Here, we report an enantiomeric pair of zero-dimensional hybrid copper bromides, (18C6@S/R-CHEA)₂Cu₄Br₆ (abbreviated as S/R-CHEACuBr, 18C6 = 18-crown-6, S/R-CHEA = (S/R)-1-cyclohexylethanamine), in which protonated S/R-CHEA⁺ is coordinated with 18C6 to form the bulky umbrella-type supramolecular cations. Such unique cations effectively isolate the inorganic [Cu₄Br₆]^2- emissive clusters and induce pronounced distortions of inorganic clusters. As a result, the obtained materials show strong circularly polarized near-infrared (CP-NIR) emission with photoluminescence quantum yields exceeding 50% and a high dissymmetry factor up to 6.8 × 10^-2. Furthermore, light-emitting diodes based on these materials exhibit high output power and distinct CP-NIR signals, offering new opportunities for NIR imaging and secure information technologies.