Low-dimensional hybrid lead-free azetidinium metal halides

Abstract Organic–inorganic hybrid halide perovskites have attracted attention in optoelectronics and photovoltaics. However, the Pb-content in the crystal structure and instability issues have raised questions about the industrialization of these materials. Bi and Sb are widely considered as an alternative on the B-site due to their isoelectronic configuration with the Pb divalent cation. Herein, we report four novel Pb-free azetidinium metal halides and present their fundamental material properties: [(CH 2 ) 3 NH 2 ] 2 AgBiBr 6 , [(CH 2 ) 3 NH 2 ] 3 Bi 2 I 9 , [(CH 2 ) 3 NH 2 ] 3 Bi 2 Br 9 , and [(CH 2 ) 3 NH 2 ] 3 Bi 2 Cl 9 . Our materials have a low-dimensional perovskite-like structure from 0 to 2D, where the replacement on the B-site is based on Ag + /Bi 3+ and Bi 3+ . Graphical Abstract As a potential light absorber, four different azetidinium metal halides were successfully synthesized via evaporation. The polycrystalline powders and thin films of the azetidinium metal halides present low dimensionalities from 0 to 2D.