J. Phys. IV France 123 (2005) 259-263
Luminescent properties of Eu3+-doped yttrium or gadolinium phosphatesD.C. Tuan1, R. Olazcuaga2, F. Guillen2, A. Garcia2, B. Moine3 and C. Fouassier2
1 Center of Analytical Services and Experimentation, Department of Industry, Natural Resources and Environment, O2 Nguyen Van Thu Street, District 1, Ho Chi Minh Ville, Vietnam
2 Institut de Chimie de la Matière Condensée de Bordeaux (ICMCB-CNRS), Université Bordeaux 1, 87 avenue du Dr. A. Schweitzer, 33608 Pessac Cedex, France
3 Laboratoire de Physico-Chimie des Matériaux Luminescents, Université Lyon 1, 43 Bd. du 11 Novembre 1918, 69622 Villeurbanne Cedex, France
After an investigation of the formation conditions of the intermediate phases existing in the systems Y2O3-P2O5 and Gd2O3-P2O5 (R/P = 4/1, 3/1, 1, 1/2, 1/3 and 1/5 (R = Y or Gd)) the luminescence characteristics of the Eu3+ ion substituted for the Y3+ or Gd3+ ions have been determined. The position of the O Eu3+ charge transfer band shifts to higher energies with increasing P content, which results in high quantum efficiencies for several P-rich phosphates. With increasing P content the probability of the electric dipole transitions is reduced, in particular for the hypersensitive 5D F2 transition. This causes a shift of the colour point to the orange and lengthens the luminescence lifetime. The luminescence characteristics are compared with those of the red phosphors for display.
© EDP Sciences 2005