Growth and Photoluminescence of Epitaxial CeO₂ Film on Si (111) Substrate

CeO₂ film with a thickness of about 80 nm was deposited by a mass-analyzed low-energy dual ion beams deposition technique on Si (111) substrate. Reflection high-energy electron diffraction and x-ray diffraction measurements showed that the film is a single crystal. The tetravalent state of Ce in the film was confirmed by x-ray photoelectron spectroscopy measurement, indicating that stoichiometric CeO₂ was formed. Violet/blue light emission (379.5 nm) was observed at room temperature, which may be tentatively explained by charge transitions from the 4f band to the valence band of CeO₂.