title: Site-selective spectroscopy in Sm(3+)-doped sol-gel-derived nano-glass-ceramics containing SnO(2) quantum dots.
abstract: Nano-glass-ceramics of composition 95SiO(2)-5SnO(2) doped with 0.4 Sm(3+) (mol%) were synthesized by the thermal treatment of precursor sol-gel glasses. Structural and luminescence measurements were carried out. The precipitated SnO(2) nanocrystals in the glass matrix constitute a wide bandgap quantum-dot system with size comparable to the bulk exciton Bohr radius. A site-selective excitation, by energy transfer from the semiconductor host, reveals that a fraction of the Sm(3+) ions are incorporated in the SnO(2) nanocrystals, whereas the rest remains in the silica glassy phase. An evolution in the Sm(3+) emission spectra has been observed when the SnO(2) nanocrystals are excited with different UV wavelengths, which has been ascribed to selective excitation of nanocrystal sets with predetermined size.
authors: Departamento de Física Básica, Universidad de La Laguna, E-38206 La Laguna, Tenerife, Spain.
authors: A C
authors: AC
authors: Yanes
authors: J J
authors: JJ
authors: Velázquez
authors: J
authors: J
authors: Del-Castillo
authors: J
authors: J
authors: Méndez-Ramos
authors: V D
authors: VD
authors: Rodríguez