Fluorinated 2D Lead Iodide Perovskite Ferroelectrics.

Hybrid perovskite materials are famous for their great application potential in photovoltaics and optoelectronics. Among them, lead-iodide-based perovskites receive great attention because of their good optical absorption ability and excellent electrical transport properties. Although many believe the ferroelectric photovoltaic effect (FEPV) plays a crucial role for the high conversion efficiency, the ferroelectricity in CH NH PbI is still under debate, and obtaining ferroelectric lead iodide perovskites is still challenging.

A Nickel(II) Nitrite Based Molecular Perovskite Ferroelectric.

The X-site ion in organic-inorganic hybrid ABX perovskites (OHPs) varies from halide ion to bridging linkers like HCOO , N , NO , and CN . However, no nitrite-based OHP ferroelectrics have been reported so far. Now, based on non-ferroelectric [(CH ) N][Ni(NO ) ], through the combined methodologies of quasi-spherical shape, hydrogen bonding functionality, and H/F substitution, we have successfully synthesized an OHP ferroelectric, [FMeTP][Ni(NO ) ] (FMeTP=N-fluoromethyl tropine).