Potassium-Sodium-Niobate-Based Thin Films: Lead Free for Micro-Piezoelectrics

摘要

Extensive research and great progress of (K,Na)NbO3 (KNN)-based lead-free piezoelectric films have been driven by the current legislation and the requirement for sustainable development of society and environment in the applications of microelectromechanical systems. A comprehensive discussion of the recent achievement in KNN-based films is presented herein. First, the available synthetic techniques, chemical modification, the ferroelectric and piezoelectric properties of KNN-based films are reviewed, followed by an introduction of the crystal structures and electrical properties of KNN-based epitaxial films in comparison with the bulk ceramics. Finally, the applications of KNN-based films for the sensors, the energy harvesters, and energy storage devices are addressed, and current challenges and prospects for future work are discussed.