Heat-sensitive structural phase transitions of hybrid halide perovskite with double dielectric ON/OFF switches

Abstract

A research domain on the ferroelectric and dielectric switching characteristics of hybrid perovskites has been opened because of their excellent physical/chemical features upon exposure to CH₃NH₃PbI₃. To promote the development of applications, designing novel systems with superior performances is crucial. Here, we found [(CH₃)₃NOH][CdCl₃], a hybrid perovskite, could be considered to be a multi-stable switchable dielectric material at high temperatures. The temperature-dependent crystal structure and differential scanning calorimetry studies revealed that it underwent three phases at low, intermediate and high temperature. Moreover, the origin of the phase transitions could be ascribed mainly to the order–disorder of trimethylamine N-oxide cations. When the temperature increased from low to high, [(CH₃)₃NOH][CdCl₃] displayed a sequential switching effect with the dynamic change of organic cations. These findings provide an excellent model to develop molecule-based compounds as multi-switch materials.