Ag nanoaggregates as efficient broadband sensitizers for Tb3+ ions in silica-zirconia ion-exchanged sol-gel glasses and glass-ceramics
Journal article, 2018
In this paper we report the study of down-shifting silica-zirconia glass and glass-ceramic films doped by Tb3+ions and Ag nanoaggregates, which combine the typical spectral properties of the rare-earth-ions with the broadband sensitizing effect of the metal nanostructures. Na-Tb co-doped silica-zirconia samples were obtained by a modified sol-gel route. Dip-coating deposition followed by annealing for solvent evaporation and matrix densification were repeated several times, obtaining a homogeneous crack-free film. A final treatment at 700 °C or 1000 °C was performed to control the nanoscale structural properties of the samples, resulting respectively in a glass (G) or a glass-ceramic (GC), where tetragonal zirconia nanocrystals are surrounded by an amorphous silica matrix. Ag introduction was then achieved by ion-exchange in a molten salt bath, followed by annealing in air to control the migration and aggregation of the metal ions. The comparison of the structural, compositional and optical properties are presented for G and GC samples, providing evidence of highly efficient photoluminescence enhancement in both systems, slightly better in G than in GC samples, with a remarkable increase of the green Tb3+PL emission at 330 nm excitation: 12 times for G and 8 times for GC samples. Furthermore, after Ag-exchange, the shape of Tb3+excitation resembles the one of Ag ions/nanoaggregates, with a broad significant absorption in the whole UV-blue spectral region. This broadband enhanced downshifting could find potential applications in lighting devices and in PV solar cells.
Downshifting
Sol-gel
Broadband sensitizers
Ag nanoaggregates
Rare earths
Author
F. Enrichi
Enrico Fermi Historical Museum of Physics and Study and Research Centre
Luleå University of Technology
Universita Ca' Foscari Venezia
S. Belmokhtar
Université Abdelmalek Essaâdi
A. Benedetti
Universita Ca' Foscari Venezia
A. Bouajaj
Université Abdelmalek Essaâdi
E. Cattaruzza
Universita Ca' Foscari Venezia
F. Coccetti
Enrico Fermi Historical Museum of Physics and Study and Research Centre
E. Colusso
University of Padua
M. Ferrari
National Research Council of Italy (CNR)
Enrico Fermi Historical Museum of Physics and Study and Research Centre
P. Ghamgosar
Luleå University of Technology
F. Gonella
Enrico Fermi Historical Museum of Physics and Study and Research Centre
Universita Ca' Foscari Venezia
Maths Karlsson
Chalmers, Chemistry and Chemical Engineering, Energy and Material
A. Martucci
University of Padua
R. Ottini
Universita Ca' Foscari Venezia
P. Riello
Universita Ca' Foscari Venezia
G. C. Righini
Enrico Fermi Historical Museum of Physics and Study and Research Centre
National Research Council of Italy (CNR)
E. Trave
Universita Ca' Foscari Venezia
A. Vomiero
Luleå University of Technology
S. You
Luleå University of Technology
L. Zur
National Research Council of Italy (CNR)
Enrico Fermi Historical Museum of Physics and Study and Research Centre
Optical Materials
0925-3467 (ISSN)
Vol. 84 668-674Subject Categories (SSIF 2011)
Atom and Molecular Physics and Optics
Materials Chemistry
Other Materials Engineering
DOI
10.1016/j.optmat.2018.07.074