Dynamically manipulated interface polarization via symmetry engineering for self-gated electronics.

Interfaces have always been a key for functional devices in condensed-matter physic. However, dynamic regulation of interfacial symmetry and the subsequent effects have still been underestimated, especially in bulk materials. Here, we show that the interfacial crystallographic symmetry can be precisely modulated by electric field induced oxygen vacancy rearrangement in bulk centrosymmetric semiconductors (TiO2, SrTiO3, etc.), resulting in tunable interface polarization. Our results show that the interface polarization of metal-semiconductor heterostructure can be reversibly modified in a nonvolatile manner, with a tunable electromechanical response varying from 6.79 to 9.07 p.m./V, which is comparable to common piezoelectric semiconductors (ZnO, GaN, MoS2, etc.). Substantial self-gated carrier transport in metal-semiconductor heterostructure is achieved, with a Schottky barrier tuned by 30.8 meV. Furthermore, the self-gated electronics effectively simplifies the complicated structures of logic devices, integrating logic and storage operations through programmable interface polarization. These findings offer a distinctive approach to design the interface symmetry and functionalities beyond the intrinsic limitation of bulk centrosymmetric materials.