Far-From-Equilibrium Processing of Ferroelectric Thin Films on Glass and Polymeric Substrates

铁电材料是一种对外界机械、电学和热场有很大响应的多功能材料。随着器件向着小型化和多功能化的方向发展，铁电薄膜作为集成在微纳机电系统中的驱动和传感、非易失性存储器和能量采集的多功能手段变得越来越重要。然而，铁电薄膜通常需要高温处理步骤，这与微电子组件的制造不相容，这是设备和控制单元完全小型化所必需的。该奖项支持对一种新的、远离平衡的加工方法的研究，该方法能够在聚合物和其他柔性基板上直接加工铁电材料。这种加工方法将实现完全集成、小型化、多功能的传感器和执行器，在医疗保健(成像片、自供电植入式传感器)、汽车(振动能量采集驱动的压力传感器、加速度计、热像仪)、安全(毫米尺寸的自主机器人)、柔性电子产品和高分辨率共形、剥离和棒状传感器中具有广泛的应用。这项工作的总体目标是通过了解通过远离平衡的工艺条件制造的铁电薄膜的工艺-结构-性能关系，实现铁电薄膜与CMOS兼容和柔性衬底的直接集成。这种加工方法(特别是脉冲热处理，PTP)允许在聚合物和柔性衬底上直接结晶钙钛矿薄膜。在玻璃和聚合物基板上加工的这些电陶瓷薄膜中，由于远离平衡的工艺条件产生的大量缺陷以及最小的残余应力，预计都将显著影响其最终的功能响应。样品将通过化学溶液沉淀法合成，并通过PTP晶化。结构和微结构表征将与薄膜的微观和宏观功能响应评估相结合。了解介观加工-结构-性能关系将使变革性的新器件应用成为可能，并为从根本上理解原子缺陷与这些功能材料的宏观响应之间的关联铺平道路。

Ferroelectric materials are multifunctional materials exhibiting large response to external mechanical, electrical and thermal fields. As devices are driven towards miniaturization and multifunctionality, ferroelectric thin films become increasingly important as a multifunctional means for actuation and sensing, non-volatile memories, and energy harvesting, integrated within micro and nano-electromechanical systems. However, ferroelectric thin films typically require a high-temperature processing step, incompatible with microelectronic component fabrication, required for the full miniaturization of the device and control units. This award supports the investigation of a novel, far-from-equilibrium processing method, enabling direct processing of ferroelectric materials on polymer and other flexible substrates. This processing method will enable fully integrated, miniaturized, multifunctional sensors and actuators, with a wide range of applications in healthcare (imaging pills, self-powered implanted sensors), automotive (vibration energy harvesting powered pressure sensors, accelerometers, thermal cameras), security (mm-sized autonomous robots), flexible electronics, and high-resolution conformal, peel-and-stick sensors.The overarching goal of this work is to enable direct integration of ferroelectric thin films with CMOS-compatible and flexible substrates, through understanding of processing-structure-property relationships in ferroelectric thin films manufactured through far-from-equilibrium processing conditions. Such a processing method (specifically pulsed thermal processing, PTP) allows direct crystallization of perovskite thin films on polymeric and flexible substrates. It is expected that both the large concentration of defects arising from the very far-from-equilibrium processing conditions as well as minimal residual stresses in these electroceramic films processed on glass and polymeric substrates will significantly influence their ultimate functional response. The samples will be synthesized through chemical solution deposition and crystallized through PTP. Structural and microstructural characterization will be coupled with micro- and macroscopic functional response evaluation of the films. Understanding mesoscale processing-structure-property relationships will enable transformative new device applications, and pave the way for a fundamental understanding of the atomistic defect landscape correlation with the macroscopic response of these functional materials.