Paul Tufan, Sahoo Aditi, Maiti Soumen, Gavali Deepak S, Thapa Ranjit, Banerjee Rupak
Department of Physics, Indian Institute of Technology Gandhinagar, Palaj, Gandhinagar 382355 India.
St. Thomas College of Engineering & Technology, Kolkata 700023, India.
ACS Appl Mater Interfaces. 2023 Jul 26;15(29):34726-34741. doi: 10.1021/acsami.3c04031. Epub 2023 Jul 13.
The main challenges impeding the widespread use of organic-inorganic lead halide perovskites in modern-day technological devices are their long-term instability and lead contamination. Among other environmentally convivial and sustainable alternatives, CsSnX (X = Cl, Br, and I) compounds have shown promise as ambient-stable, lead-free materials for energy harvesting, and optoelectronic applications. Additionally, they have demonstrated tremendous potential for the fabrication of self-powered nanogenerators in conjunction with piezoelectric polymers like polyvinylidene-fluoride (PVDF). We report on the fabrication of composites constituting solvothermally synthesized CsSnX nanostructures and PVDF. The electroactive phases in PVDF were boosted by the incorporation of CsSnX, leading to enhanced piezoelectricity in the composites. First-principles density functional theory (DFT) studies were carried out to understand the interfacial interaction between the CsSnX and PVDF, which unravels the mechanism of physisorption between the perovskite and PVDF, leading to enhanced piezoresponse. The halide ions in the inorganic CsSnX perovskites were varied systematically, and the piezoelectric behaviors of the respective piezoelectric nanogenerators (PENGs) were investigated. Further, the dielectric properties of these halide perovskite-based hybrids are quantified, and their piezoresponse amplitude, piezoelectric output signals, and charging capacity are also evaluated. Out of the several films fabricated, the optimized CsSnI_PVDF film shows a piezoelectric coefficient () value of ∼200 pm V and a remanent polarization of ∼0.74 μC cm estimated from piezoresponse force microscopy and polarization hysteresis loop measurement, respectively. The optimized CsSnI_PVDF-based device produced an instantaneous output voltage of ∼167 V, a current of ∼5.0 μA, and a power of ∼835 μW across a 5 MΩ resistor when subjected to periodic vertical compression. The output voltage of this device is used to charge a capacitor with a 10 μF capacitance up to 2.2 V, which is then used to power some commercial LEDs. In addition to being used as a pressure sensor, the device is employed to monitor human physiological activities. The device demonstrates excellent operational durability over a span of several months in an ambient environment vouching for its exceptional potential in application to mechanical energy harvesting and pressure sensing applications.
阻碍有机-无机铅卤化物钙钛矿在现代技术设备中广泛应用的主要挑战是其长期不稳定性和铅污染。在其他环境友好且可持续的替代材料中，CsSnX（X = Cl、Br和I）化合物已显示出有望成为用于能量收集和光电子应用的环境稳定、无铅材料。此外，它们在与聚偏二氟乙烯（PVDF）等压电聚合物结合制造自供电纳米发电机方面展现出巨大潜力。我们报道了由溶剂热合成的CsSnX纳米结构和PVDF构成的复合材料的制备。通过掺入CsSnX增强了PVDF中的电活性相，从而提高了复合材料的压电性。进行了第一性原理密度泛函理论（DFT）研究以了解CsSnX与PVDF之间的界面相互作用，这揭示了钙钛矿与PVDF之间的物理吸附机制，从而导致增强的压电响应。对无机CsSnX钙钛矿中的卤离子进行了系统变化，并研究了相应压电纳米发电机（PENGs）的压电行为。此外，对这些基于卤化物钙钛矿的杂化物的介电性能进行了量化，并评估了它们的压电响应幅度、压电输出信号和充电容量。在所制备的几种薄膜中，优化后的CsSnI_PVDF薄膜通过压电响应力显微镜和极化滞后回线测量分别显示出约200 pm V的压电系数（）值和约0.74 μC cm的剩余极化。优化后的基于CsSnI_PVDF的器件在受到周期性垂直压缩时，在5 MΩ电阻上产生了约167 V的瞬时输出电压、约5.0 μA的电流和约835 μW的功率。该器件的输出电压用于对一个10 μF电容的电容器充电至2.2 V，然后用于为一些商用LED供电。除了用作压力传感器外，该器件还用于监测人体生理活动。该器件在环境中几个月的时间跨度内表现出出色的操作耐久性，证明了其在机械能收集和压力传感应用中的卓越潜力。
