Photoluminescence of Eu3+ in silicate-based phosphors by near-infrared and near-ultraviolet excitation for multifunctional applications.

• New Eu3+/Yb3+ doped LSO phosphors were designed. • The LSO:20%Eu3+ shows a much higher brightness than the commercial Y 2 O 3 :Eu3+. • The LSO:Eu3+ shows a higher T 0.5 value than many other phosphors. • The developed phosphors are promising for multifunctional applications. In this work, a series of Eu3+/Yb3+ doped La 1.55 SiO 4.33 (LSO) phosphors were prepared by solid state reaction method for multifunctional applications. The phase purity and particle morphology were characterized with XRD and SEM technique, respectively. Upon ultraviolet light excitation, the downshifting luminescence of Eu3+ was observed in the red region, and the strongest emission peak located at 612 nm is attributed to the forced electric dipole 5D 0 →7F 2 transition. The optimal Eu3+ doping concentration was determined to be 20 mol%, for which the internal quantum efficiency of the phosphor reaches 75.1%. The temperature-dependent emission spectra of LSO:20%Eu3+ revealed that the quenching temperature T 0.5 is 483 K. For the upconversion (UC) luminescence, the Yb3+-Eu3+ codoped LSO phosphors were designed, where the Yb3+ ion was used as a sensitizer. The UC mechanism for a cooperative energy transfer was learnt from the pump-power-dependent emission spectra. By excitation at various temperatures, the intensities of emissions from different excited states showed different changes with temperature. All the above spectral characteristics indicate that the LSO:Eu3+/Yb3+ phosphors can show potential applications in LEDs, anticounterfeiting and optical thermometer. [ABSTRACT FROM AUTHOR]