Photoluminescence and local structure analysis of Sm~(3+) ions in single phase TiO_(2) thin films

摘要

Single phase TiO_(2): Sm~(3+) thin films (anatase: A- or rutile: R-) have been fabricated on Si substrates by laser ablation with controlled O_(2) pressure during film preparation. Visible photoluminescence (PL) originating from the intra-4f transitions in Sm~(3+) ions were observed at room temperature. The A-TiO_(2):Sm~(3+) thin films exhibited more intense Sm~(3+)-related PL than that of R-TiO_(2):Sm~(3+), resulting from the difference of Sm~(3+) configuration in the host crystal matrixes. A phase transition from anatase to rutile of the host changed the local crystal symmetry of the Sm~(3+) ions and extinguished the Sm~(3+)-related PL, even there was no significant change on the Sm concentration.