Highly Emissive Chiral Indium‐Based Perovskite Single Crystals for Efficient Optoelectronic Applications

Abstract Chiral lead halide perovskites have captivated considerable attentions due to their distinctive attributes, such as ferroelectricity, spin‐dependent transport, and chiroptical activity. However, lead toxicity and weak circularly polarized luminescence (CPL) have cast a pall over their practical applications. Here, a series of 0D lead‐free chiral enantiomorphic hybrids, such as ( R ‐/ S ‐MBA) 3 In 1‐ x Sb x Cl 6 (x = 0–1) is successfully developed. By optimizing the Sb 3+ doping concentration to 0.55%, the resultant ( R ‐/ S ‐MBA) 3 In 99.45% Sb 0.55% Cl 6 not only shows a near‐unity quantum yield but also emanates potent CPL, boasting a dissymmetry factor ( g lum ) of 6.3 × 10 –3 . These efficient CPL activities are intricately tied to the presence of a twisted luminescent cluster [SbCl 6 ] 3– induced by structural chirality. The comprehensive results reveal that the emission of the chiral perovskite originated from self‐trapped excitons (STEs) of 5s 2 Sb 3+ ions. Moreover, (MBA) 3 In 99.45% Sb 0.55% Cl 6 single crystals also exhibit bright orange emission and UV detector signals. These findings will pave the way for the further investigation in efficient CPL and detectors based on lead‐free chiral optoelectronic materials.