A semiconducting organic-inorganic hybrid perovskite-type non-ferroelectric piezoelectric with excellent piezoelectricity.

Piezoelectric materials are a class of important functional materials applied in high-voltage sources, sensors, vibration reducer, actuators, motors, and so on. Herein, [(CH3)3S]3[Bi2Br9](1) is a brilliant semiconducting organic-inorganic hybrid perovskite-type non-ferroelectric piezoelectric with excellent piezoelectricity. Strikingly, the value of piezoelectric coefficient d33 is estimated about 18 pC/N. Such a large piezoelectric coefficient in non-ferroelectric piezoelectricity has been scarcely reported, comparable with those of typically one-composition non-ferroelectric piezoelectricity such as ZnO (3 pC/N) and much greater than those of most known typical materials. And 1 exhibits semiconducting behaviour with an optical band gap of ~2.58 eV that is lower than reported 3.37 eV of ZnO. This discovery open a new avenue to exploit molecular non-ferroelectric piezoelectricity and should enlighten further exploration of non-ferroelectric piezoelectricity due to their high stability and low loss characteristics.