Recent Advances in Layered Two-dimensional Ferroelectrics from Material to Device

With the advent of the post Moore era, modern electronics require further device miniaturization of all electronic components, particularly ferroelectric memories, due to the need for massive data storage. This demand stimulates the exploration of robust switchable ferroelectric polarizations at the atomic scale. In this scenario, van der Waals ferroelectrics have recently gained increasing attention because of their stable layered structure at nanometer thickness, offering the opportunity to realize two-dimensional ferroelectricity that is long-sought in conventional thin film ferroelectrics. In this review, recent advancements are summarized in layered ferroelectrics with highlights of the fundamentals of intrinsic two-dimensional ferroelectricity, the emergence of artificial stacking ferroelectricity, and related protype devices with exotic functions. In addition, the unique polarization control in van der Waals ferroelectrics is discussed. Although great challenges remain unsolved, these studies undoubtedly advance the integration of 2D ferroelectrics in electronics.