Atomic and electronic structures at ZnO and ZrO2 interface for transparent thin‐film transistors

In this paper, we report the studies of atomic and electronic structures at ZnO and ZrO2 interface. The epitaxial heterostructures were grown by laser molecular beam epitaxy and the interface atomic structure was determined by using high‐resolution transmission electron microscopy (TEM). Band alignment for high‐k ZrO2 layer on ZnO was investigated by in situ X‐ray photoemission spectroscopy (XPS) characterization and first‐principles calculations based on density functional theory (DFT). The valence and conduction band offsets (CBOs) were found to be 0.27 ± 0.05 eV and 2.16 ± 0.05 eV, respectively. The results are in good agreement with values from theoretical calculations. The large CBO and small lattice mismatch between ZnO and ZrO2 suggest potential for ZrO2 to be used as a gate dielectric in ZnO‐based transparent electronic devices.