Zero-dimensional organic–inorganic hybrid antimony bromide with efficient broadband orange emission and nonlinear optical response

The development of lead-free hybrid metal halides with multiple optical properties is essential for advancing perovskite-based optical materials, though it remains challenging. Herein, we synthesized a zero-dimensional (0D) hybrid antimony-based halide, [DMPZ]₂SbBr₆ Br·3H₂O (DP-SbBr, DMPZ = <i>N</i>,<i>N</i>'-Dimethylpiperazine), <i>via</i> precise molecular-level design, which exhibits both efficient photoluminescence (PL) and nonlinear optical (NLO) properties. Notably, DP-SbBr crystallizes in the <i>P</i>2₁2₁2 chiral space group, despite lacking chiral units, with isolated [SbBr₆]^3- octahedral units separated by organic molecules, forming a typical 0D hybrid structure. This unique structure enables efficient orange light emission with a 28.5% quantum yield. Additionally, DP-SbBr demonstrates a 0.32-fold second-harmonic generation (SHG) signal relative to KDP, showcasing its potential as a NLO material. This work lays the foundation for designing multifunctional hybrid perovskite-based optical materials at the molecular level.