Neutral 1D Perovskite-Type ABX₃ Ferroelectrics with High Mechanical Energy Harvesting Performance

Organic–inorganic ABX3 hybrids with perovskite structures have drawn enormous attention owing to their intriguing chemical variability, structural tunability, and diversity of application-worthy properties. Herein, we report the synthesis of a new neutral ABX3 hybrid ferroelectric compound [Me3NCH2CH2OH]CdCl3 (1), which exhibits a 1D chain structure of edge-sharing CdCl5O octahedra that are connected to cationic [Me3NCH2CH2OH]+ units via its peripheral OH functionality. The single-crystal X-ray diffraction analysis of the compound at 363 K reveals the conversion of 1 to its coordination isomer 1′, in which the anionic chain consists of face-sharing CdCl6 octahedra and the cations are uncoordinated. The piezoresponsive force microscopy analysis performed on a single crystal of 1 confirms the existence of polarizable domains in it. The ferroelectric P–E loop measurements on 1 show a high remnant polarization value of 17.1 μC cm–2. Composite devices based on 1 and polydimethylsiloxane (PDMS) prepared with varying wt % compositions are examined for mechanical energy harvesting applications. The highest open-circuit voltage of 55.2 V and a maximum power density of 70.9 μW cm–2 at an optimal load of 4 MΩ were obtained for the 15 wt % 1–PDMS device. The harvested energy is shown to be effective for capacitor charging and light-emitting diode (LED) flash lighting applications.