Atomic Manipulation of Metal Oxide Heterointerfaces by Electron Beam Illumination

Constructing heterointerfaces with space charge areas can effectively drive carrier transport. However, it is difficult to further enhance the interfacial bond strength to improve the built-in potential difference across the interface by directly modulating the interfacial atomic configuration. Herein, we have directly regulated the atomic structures of ZnO/CoO heterointerfaces by means of the phase transition of the rocksalt CoO to spinel Co₃O₄ under a high-energy electron beam. The results show that irradiation of electron beams can drive the orderly migration and aggregation of Co vacancies as well as the rearrangement of lattice Co atoms from octahedral sites to tetrahedral sites, causing the formation of spinel Co₃O₄. DFT calculations demonstrate that O atoms adjected to four-coordinated Co atoms are strongly coupled with the Zn atoms, enhancing interfacial polarization to facilitate the charge transfer. This finding provides a novel idea for the design of heterojunctions with high-efficiency charge transport.