Synthesis and properties of luminescent Y2O3 : Tb3+ (5, 8 12 wt.%) nanocrystals

We have studied the photoluminescence (PL) characteristics of Y2O3:Tb3+ (5 wt.% <= Tb <= 12 wt.% composition) nanocrystal from the viewpoint of particle size, annealing effect, amount of Tb3+ concentration and PL decay time. Nanoscale Y2O3:Tb3+ was synthesized by a liquid-phase reaction method using yttrium acetylacetonate hydrate [CH3COCH=C(O-)CH3](3)Y center dot xH(2)O as a precursor for the host lattice and [CH3CO2](3)Tb center dot xH(2)O for the terbium doping. Both were dissolved in methanol at room temperature and dried at 120 degrees C. The synthesized Y2O3:Tb3+ was annealed at 300 degrees C, 400 degrees C and 500 degrees C during 1 h in air. The particle size and PL intensity of the Y2O3:Tb3+ nanocrystal are significantly dependent on the annealing temperature and Tb3+ concentration. At 400 degrees C of annealing temperature and 8 wt.% of Tb3+ doping concentration, the crystallinity and PL characteristic of the Y2O3:Tb3+ are improved meaningfully. The dominant D-5(4)-F-7(J) (green emission, J= 6,5,4,3,...) transition, with sharp D-5(4)-F-7(5) peak, due to the cross relaxation is observed and the corresponding PL decay time is estimated as 2.15 ms, However, it needs to understand detailed decay behavior of Y2O3:Tb3+ and it should also be pointed out that a rigorous analysis could be applied furthermore. (C) 2006 Elsevier B.V. All rights reserved.