Optical properties of rare-earth ion (Gd3+, Ho3+, Pr3+, Sm3+, Dy3+ and Tm3+)-doped alumina films prepared by the sol-gel method

Rare-earth ions (Gd3+, Ho3+ pr(3+), Sm3+, Dy3+ and Tm3+)-doped alumina film s were prepared by the sol-gel method, using aqueous AlCl3-derived alumina sol. The ions were highly doped into alumina by this method (similar to 15 mol% per alumina). Then, the absorption and fluorescence spectra of the dop ed films were measured. The first three ion-doped films showed quenching at higher concentrations ( > 15 mol%) and the last three ion-doped films quen ching at lower concentrations (greater than or equal to0.5mol%). The quench ing composed of a fast component and the slow one which depended on differe nt sites of disordered alumina. (C) 2001 Elsevier Science B.V. All rights r eserved.