Structural and Optical Properties of SrTi_1-xSc_xO₃ Thin Film Prepared by RF Magnetron Sputtering

Abstract

Sc-doped SrTiO₃ (SrTi_0.99Sc_0.01O₃) thin film have prepared on MgO (001) substrate by RF magnetron sputtering using ceramic target. The substitution of Sc³⁺ ions was confirmed by X-ray absorption spectroscopy. The thin film prepared at the substrate temperature of 700℃ was crystallized by postannealing in O₂ atmosphere at 800℃. The thin film exhibited a-axis orientation. The postannealed thin film was transparent The fundamental absorption edge of SrTi_0.99Sc_0.01O₃ thin film shifts to lower wavelength side than that of SrTiO₃ thin film. The valence band and conduction band measured by soft-X-ray spectroscopy are in good agreement with the calculated band-DOS. The energy separation between the top of the valence band and the bottom of the conduction band of the thin film is estimated to be ～3.5 eV