Ultra-thin ferroelectrics
Huimin Qiao, Chenxi Wang, Woo Seok Choi, Min Hyuk Park, Yunseok Kim
Abstract
Device applications of ferroelectrics have not only utilized the switchable polarization but also adopted myriads of emerging physical properties. In particular, ferroelectrics in ultra-thin limit have recently attracted considerable scientific and technological interest owing to the increasing demand for miniaturization of electronic devices. In the last two decades, ultra-thin ferroelectrics have rapidly developed with the advances in the theoretical calculations, synthesis, and characterization techniques. However, atomic-scale realization and rigorous characterization of ultra-thin ferroelectricity remain challenging. In this review, we summarize state-of-the-art researches on ultra-thin ferroelectrics. We provide a brief overview of the history and underlying mechanism of ferroelectrics in the context of ultra-thin ferroelectrics. In particular, we discuss complex transition metal oxide ultra-thin ferroelectrics, ferroelectric two-dimensional materials, and fluorite HfO2-based ultra-thin ferroelectrics. Further, we discuss the characterization techniques used to verify the ultra-thin limit of ferroelectricity, followed by device applications based on various emergent properties of ultra-thin ferroelectrics. Finally, we provide a brief conclusion and outlook. © 2021 The Author(s)