Synthetic-Method-Dependent Antimony Bromides and Their Photoluminescent Properties

Recently, excellent optical properties of low-dimensional organic–inorganic metal halides, stemming from their tunable structure and optoelectronic properties, have been demonstrated. The synthetic method is critical because it is highly related to the structure and properties of the halide. Herein, we obtain two different antimony bromides, (Bmpip)2SbBr5 and (Bmpip)3Sb2Br9, which both possess the P21/c space group having different crystal structures, and this confirms the important influence of synthesis on the single-crystal structure. (Bmpip)2SbBr5 contains Bmpip+ and [SbBr5]2– pyramids, and (Bmpip)3Sb2Br9 consists of Bmpip+ and Sb-based dimers [Sb2Br9]3–. Under 400 nm excitation, (Bmpip)2SbBr5 exhibits a 640 nm orange emission with a quantum yield of ∼11.5% owing to Sb 5s2 electron luminescence. A diode was fabricated by (Bmpip)2SbBr5 and commercial phosphors and showed a high color render index of 92. Our work reveals the effect of the preparation method on the crystal structure. A luminescent material was finally identified.