EU3+-based optical centers with a high efficiency of the 5D0 → 7F4 transition in alumina gel films

A record peak luminescence intensity of the D-5(0) -> F-7(4) transition in Eu3+ ions and broadening of their UV excitation band are obtained by doping of Eu-containing alumina gel films with bismuth oxyfluoride and subsequent thermal treatment at T >= 700 degrees C. The results obtained are explained by the formation of complex Eu-Bi centers with C-3v symmetry in the Al2O3 structure, efficient migration of excitations from EuAlO3 crystallites to these centers, and the sensitization of the luminescence of the rare-earth activator by Bi3+ ions. (C) 2005 Pleiades Publishing, Inc.