Effects of the Si-nanocluster size on the sensitizing role towards Er ions
SIFCOM, CNRS UMR 6176, ENSICAEN, 6 Boulevard du Maréchal-Juin, 14050 Caen Cedex, France
Corresponding author: a email@example.com
Revised: 20 April 2006
Published online: 13 June 2006
The effects of Si nanocluster (Si-nc) size on the energy transfer rate to Er ions were investigated through studies made on appropriate configurations of mutilayers (MLs) consisting in about 20 periods of Er-doped Si-rich SiO2/SiO2. These MLs were deposited by reactive magnetron sputtering at 650 °C and subsequently annealed at 900 °C. For Si-rich layer thickness or Si-nc larger than about 4 nm, the sensitizing effect of Si-nc towards rare earth ions is highly lowered because of the weak confinement of carriers and the loss of resonant excitation of Er through the upper levels (second, third, ...). The latter is liable to prevent the energy back transfer process, while the weak confinement reduces strongly the probability of no phonon radiative recombination necessary for the energy transfer from Si-nc to Er ions.
PACS: 78.55.-m – Photoluminescence, properties and materials / 78.67.Pt – Multilayers; superlattices / 81.15.Cd – Deposition by sputtering
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2006