Electronic structure and optical properties of Nb doped Al2O3 on Si by atomic layer deposition

Nb2O5 and Nb doped Al2O3 have proved to be good candidates as resistive switch materials or optical materials. In this letter, we focus on the complex electronic structure and optical properties of Nb doped Al2O3 to give chemical physical images of the films. With the help of SE, XPS and XPS valence band spectra, the detailed electronic structure with atomic bonding structure and optical properties are given. The band gap of a thin oxide film is determined to be 5.05 eV, and the evolution of VBO and CBO of the film on Si are also discussed.