Synthesis and photoluminescent characterization of ceramic phosphors LiMgGeO:Ln (Ln = Pr or Tm) under different excitation wavelengths.

In the current work, germanate phosphors LiMgGeO:Ln (Ln = Pr, Tm) have been synthesized and then investigated using luminescence spectroscopy. The X-ray diffraction analysis demonstrate that ceramic compounds LiMgGeO containing Pr and Tm ions crystallize in a monoclinic crystal lattice. Luminescence properties of Pr and Tm ions have been examined under different excitation wavelengths. The most intense blue emission band related to the D → F transition of Tm is overlaps well with broad band located near 500 nm, which is assigned to F-type centers. These effects are not evident for Pr ions. Ceramic phosphors LiMgGeO:Ln (Ln = Pr, Tm) are characterized based on measurements of the excitation/emission spectra and their decays. The experimental results indicate that germanate ceramics LiMgGeO doped with trivalent rare earth ions can be applied as inorganic phosphors emitting orange (Pr) or blue (Tm) light.