Bright upconversion white light emission in transparent glass ceramic embedding Tm3+/Er3+/Yb3+:β-YF3 nanocrystals

Intense red (Er3+:F-4(9/2)-> I-4(15/2), Tm3+:(1)G(4)-> F-3(4)), green (Er3+:H-2(11/2), S-4(3/2)-> I-4(15/2)), and blue (Tm3+:D-1(2)-> F-3(4), (1)G(4)-> H-3(6)) upconversion emissions were simultaneously generated in the transparent glass ceramics containing Tm3+/Er3+/Yb3+:beta-YF3 nanocrystals under single 976 nm laser excitation. It was demonstrated that Tm3+ behaves as the sensitizer for red luminescence of Er3+ and Er3+ as the quenching center for blue, red, and near-infrared upconversion emissions of Tm3+. Various colors of the luminescence, including perfect and bright white light with CIE-X=0.310 and CIE-Y=0.358, can be easily tuned by adjusting the concentrations of the rare earth ions in the material. (c) 2007 American Institute of Physics.