Interface Phenomena and Emerging Functionalities in Ferroelectric Oxide Based Heterostructures

Abstract

Leveraging the nonvolatile, nanoscale controllable polarization, ferroelectric perovskite oxides can be integrated with various functional materials for designing emergent phenomena enabled by interfacial coupling meditated by charge, lattice, and polar symmetry, as well as constructing novel energy-efficient electronics and nanophotonics with programmable functionalities. When prepared in thin films or membrane forms, the ferroelectric instability of these materials is highly susceptible to the interfacial electrostatic and mechanical boundary conditions, resulting in tunable polarization field, Curie temperature, and domain formation. This feature article focuses on two types of ferroelectric oxide-based heterostructures: epitaxial perovskite oxide heterostructures and ferroelectric oxides interfaced with 2D van der Waals materials. The topics covered include the basic synthesis methods and property characterizations of ferroelectric oxide thin films, membranes, and heterostructures, various emergent phenomena hosted by the heterostructures, including the polarization-controlled metal-insulator transition and magnetic anisotropy, negative capacitance effect, domain imposed 1D graphene superlattices, programmable second harmonic generation, and interface enhanced polar alignment and piezoelectric response, as well as their applications in nonvolatile memory, logic, and reconfigurable optical applications. Possible future research directions are also outlined, encompassing the synthesis via remote epitaxy and oxide moiré engineering, incorporation of binary ferroelectric oxides, functional design of oxygen octahedral rotation, and realization of topological functionalities.