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.具有钙钛矿（perovskite）结构的有机-无机ABX3杂化材料因其独特的化学可变性、结构可调性及诸多具备应用价值的性能而受到广泛关注。本文报道了一种新型中性ABX3型杂化铁电化合物[Me3NCH2CH2OH]CdCl3（编号1），其具有由共边连接的CdCl5O八面体构成的一维链状结构，该八面体通过外围的羟基与阳离子[Me3NCH2CH2OH]+单元相连。对该化合物在363 K下的单晶X射线衍射（single-crystal X-ray diffraction）分析表明，化合物1可转变为其配位异构体1'：在该异构体中，阴离子链由共面连接的CdCl6八面体构成，且阳离子未与八面体配位。对化合物1的单晶开展压电力显微镜（piezoresponsive force microscopy）分析，证实了其中存在可极化畴。对化合物1开展铁电P-E回线测试，测得其剩余极化强度高达17.1 μC·cm⁻²。本研究针对由不同质量分数配比的化合物1与聚二甲基硅氧烷（polydimethylsiloxane, PDMS）制备的复合器件，开展了机械能收集应用相关测试。其中，15%质量分数的1-PDMS复合器件表现最优，其开路电压可达55.2 V，在4 MΩ最优负载下的最大功率密度为70.9 μW·cm⁻²。测试结果表明，收集得到的能量可有效用于电容器充电以及发光二极管（light-emitting diode, LED）的闪光照明应用。