Effects of the Si-nanocluster size on the sensitizing role towards Er ions F. Gourbilleau, R. Rizk, C. Dufour and R. Madelon Eur. Phys. J. B, 51 3 (2006) 341-344 Published online: 13 June 2006 DOI: 10.1140/epjb/e2006-00233-7