Organic-inorganic hybrid metal halides have received extensive attention owing to their versatile structures and optoelectronic properties. Herein, we report two lead-free metal halides, (PMA)3BiBr6and (PMA)3SbBr6[PMA+: (C6H5CH2NH3)+, as the abbreviation of phenylmethylammonium], which possess iso-structural zero-dimensional structures and crystallize in the monoclinic space groupP21/c. (PMA)3BiBr6and (PMA)3SbBr6exhibit optical band gaps of ∼3.50 and 3.40 eV, respectively, and density functional theory calculations reveal their indirect bandgap behaviors. Upon 350 and 425 nm excitation, (PMA)3BiBr6and (PMA)3SbBr6exhibit broadband emission peaking at 510 nm and 625 nm with wide full-widths at half-maximum of ∼153 and 175 nm, respectively. The emission mechanism of the metal halides is attributed to self-trapped exciton emission. The relationship between the crystal structure and luminescence intensity is also discussed. Finally, both metal halides have high decomposition temperatures and are stable for long-term storage under ambient conditions, demonstrating their potential for optoelectronic applications.
ASJC Scopus subject areas
- Materials Chemistry