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 [CH3COCHC(O–)CH3]3Y·xH2O as a precursor for the host lattice and [CH3CO2]3Tb·xH2O for the terbium doping. Both were dissolved in methanol at room temperature and dried at 120 °C. The synthesized Y2O3:Tb3+ was annealed at 300 °C, 400 °C and 500 °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 °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 5D4–7FJ (green emission, J = 6,5,4,3,…) transition, with sharp 5D4–7F5 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.