Solvent-mediated crystallization of (TMS) 2 BiBr 5 ·DMSO: a new 0D hybrid halide perovskite.

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) 2 BiBr 5 ·DMSO, stabilized by the dimethyl sulfoxide (DMSO) solvent. The structure contains isolated [BiBr 5 OS(CH 3 ) 2 ] 2- anionic polyhedra and the cations [(CH 3 ) 3 S] + (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 BiBr 5 ·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.