Two bilayer organic-inorganic hybrid perovskite compounds exhibiting reversible phase transition and dielectric anomalies

摘要: Abstract Ruddlesden-Popper two-dimensional (2D) organic-inorganic hybrid perovskites have been explored for multiple applications, benefitting from their structural tunability, superior stability and congenital quantum-well effects. Herein, two bilayer perovskite-type compounds with the general formula [A2Bn-1PbnI3n+1] (n is number of layer) [(C5H8NS)2(MA)Pb2I7] (1) [(C5H8NS)2(FA)Pb2I7] (2) (C5H8NS: 2-thiophenemethylamine, MA: methylamine, FA: formamidine) are reported. The differential scanning calorimetry (DSC) measurements revealed both 1 2 exhibit reversible phase transitions above room temperature, accompanied by dielectric anomalies near Curie temperature (Tc). variable-temperature X-ray single-crystal diffraction disclosed derive order-disorder transformation organic cations methylamine formamidine. Furthermore, exhibited strong emission peaks at about 600 ​nm when under an excitation wavelength 475 ​nm.