A Cooperative Structural Dimension and Clusters Chirality in Antimony Halide Hybrids for Efficient Circularly Polarized Electroluminescence

ABSTRACT Chiral metal–halide materials often suffer from inherent trade‐off between photoluminescence efficiency and chiroptical asymmetry ( g value); low‐dimensional structures typically deliver high emission efficiency but small g values, whereas higher‐dimensional counterparts afford larger g values at the cost of reduced luminescence efficiency. To overcome this limitation, we introduce a cluster‐level chirality strategy in a 0D framework by incorporating chiral metal halide clusters. Herein, we rationally design and synthesize a pair of enantiomeric antimony(III) halide hybrids, [(R,R)/(S,S)(PPh 2 ) 2 C 4 ] 2 [Sb 4 Cl 16 ] ( R/S‐DPPB‐Sb ) in which bulky chiral phosphonium cations template previously unreported isolated [Sb 4 Cl 16 ] 4− clusters assembled into a helical lattice. These enantiomers exhibit bright self‐trapped excitons emission at 625 nm with photoluminescence quantum yields above 40%, along with strong circularly polarized luminescence ( g lum ≈ ±7 × 10 −3 ), among the highest reported to date for chiral Antimony‐based hybrids. Remarkably, we further demonstrate circularly polarized LEDs using R/S‐DPPB‐Sb as the emitter, achieving an external quantum efficiency of 1.48% and a notable CP‐EL dissymmetry factor (| g EL | > 9 × 10 −3 ). The strong chiroptical response originates from the pronounced distortion of the [Sb 4 Cl 16 ] 4− clusters and their helical supramolecular packing. This work establishes antimony halide clusters as a promising chiral emitter and provides a viable route toward high‐performance, lead‐free CPLEDs.