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

Abstract

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.