2D dielectrics and ferroelectrics: emerging materials, physics and design principles

Dielectric and ferroelectric materials form the basis of modern electronics. Owing to their atomically-thin thickness, two-dimensional (2D) nanosheets present a tantalizing prospect of scaling dielectric/ferroelectric technologies down to a truly atomic scale. This review presents recent advances in dielectric/ferroelectric nanosheets, tracing their evolution from isolated 2D units to architected materials platforms. Access to the 2D limit reveals high- κ dielectric/ferroelectric responses distinct from bulk counterparts, while precise heterointerface engineering enables artificial superlattices with emergent functionalities such as artificial ferroelectricity and multiferroicity. Parallel progress in nanosheet-related layered perovskites, including hybrid improper ferroelectricity and Pb-free high- T C systems, underscores the richness of chemistry in layered perovskites. By enabling atomic-level design of dielectric and ferroelectric functions, 2D nanosheets and related layered systems provide a foundation for future electronic and energy technologies.