We investigated the structural and electrical properties of a-axis-oriented Sc3+-doped TiO2 (Ti0.99Sc0.01O2−δ) thin film with rutile structure prepared by RF magnetron sputtering. The prepared thin film had smaller lattice constant than that of the bulk crystal due to the stress from the substrate and a lot of oxygen vacancies. The Ti 2p photoemission (PES) spectrum exhibited the mixed valence states of Ti4+ and Ti3+. The electrical conductivity in in-plane exhibited the semiconducting-like behavior with the activation energy of ∼100 meV and electron–ion mixed conduction was obtained by oxygen partial pressure (PO2) dependence of the electrical conductivity at room temperature (R.T.). The existence of OH− peak was also observed in the O 1s PES spectrum. These results indicate that the a-axis-oriented Ti0.99Sc0.01O2−δ thin film has the electron–proton mixed conduction on the surface at R.T.
ASJC Scopus subject areas
- Physics and Astronomy(all)