Circularly Polarized Luminescence from Zero‐Dimensional Hybrid Lead‐Tin Bromide with Near‐Unity Photoluminescence Quantum Yield

摘要

Abstract Zero‐dimensional (0D) hybrid metal halides with perfect host‐guest structures are promising candidates to construct circularly polarized luminescence (CPL)‐active materials. However, it still remains challenging to obtain 0D chiral metal halides with simultaneously strong CPL and high photoluminescence quantum yield. Here, a new enantiomeric pair of 0D hybrid lead‐tin bromides, (RR/SS‐C6N2H16)2Pb0.968Sn0.032Br6 ⋅ 2H2O (R/S‐PbSnBr ⋅ H2O), is reported. The R/S‐PbSnBr ⋅ H2O compounds not only show intriguing self‐trapped exciton emissions with near‐unity quantum yield, but also present intense CPL with a dissymmetry factor glum of ±3.0×10−3. Such CPL activities originate from the asymmetric SnBr64− luminophores in R/S‐PbSnBr ⋅ H2O, due to the induced structural chirality by the organic ligands via N−H⋅⋅⋅Br hydrogen bonds. Furthermore, CPL emissions with tunable colors from R/S‐PbSnBr ⋅ H2O and dehydrated compounds are reversibly observed, which extends their chiroptical applications.