Color-tunable infrared-to-visible upconversion luminescence and intensified 1.54?m near-infrared emission in Y2O3:Yb3+, Er3+, Eu3+phosphors prepared by sol-gel method

Y2O3:Yb3+, Er3+, Eu3+ phosphors with different Yb3+, Er3+ and Eu3+ doping concentrations were prepared by sol-gel method using glycine as a chelating agent. The effect of Yb3+/Er3+/Eu3+ doping concentrations on the upconversion and near-infrared spectral performances of the synthesized phosphors were investigated. The XRD analysis shows that the samples calcined at 1000 degrees C for 2 h are well-crystallized and show a pure cubic Y2O3 phase. Upon excitation of 980 nm excitation source, the emission intensity of green/red upconversion and 1.54 mu m near-infrared emission of the samples can be adjusted with the variation of Eu3+ doping concentrations. The samples also display a color-tunable upconversion emission with the variation of Eu3+ doping concentration and the excitation power of 980 nm laser diode. In addition, the energy transfer mechanism among Yb3+, Er3+ and Eu3+ in upconversion and 1.54 mu m emission processes are also discussed.