Solvent-mediated crystallization of (TMS)2BiBr5·DMSO: a new 0D hybrid halide perovskite

Abstract

Lead-free hybrid halide perovskites have recently gained enormous research attention because of their excellent optical properties. Herein, we report a novel zero-dimensional (0D) hybrid halide perovskite, (TMS)₂BiBr₅·DMSO, stabilized by the dimethyl sulfoxide (DMSO) solvent. The structure contains isolated [BiBr₅OS(CH₃)₂]²⁻ anionic polyhedra and the cations [(CH₃)₃S]⁺ (trimethyl sulfonium ion, TMS) balance the charge, making it a 0D halide perovskite. Non-interaction of the trans Br atoms (with respect to the Bi–DMSO bond) with the cationic TMS resulted in shorter trans Bi–Br bonds as compared to other Bi–Br bonds in the isolated BiBr₅·DMSO polyhedra. The optical properties study reveals that the compound is an indirect band gap type with a band gap of 2.79 eV. From the PL study it is observed that the compound shows emission in the blue region.