Synthesis and photoluminescent characterization of ceramic phosphors Li 2 MgGeO 4 :Ln 3+ (Ln 3+ = Pr 3+ or Tm 3+ ) under different excitation wavelengths.

In the current work, germanate phosphors Li 2 MgGeO 4 :Ln 3+ (Ln = Pr, Tm) have been synthesized and then investigated using luminescence spectroscopy. The X-ray diffraction analysis demonstrate that ceramic compounds Li 2 MgGeO 4 containing Pr 3+ and Tm 3+ ions crystallize in a monoclinic crystal lattice. Luminescence properties of Pr 3+ and Tm 3+ ions have been examined under different excitation wavelengths. The most intense blue emission band related to the 1 D 2 → 3 F 4 transition of Tm 3+ is overlaps well with broad band located near 500 nm, which is assigned to F-type centers. These effects are not evident for Pr 3+ ions. Ceramic phosphors Li 2 MgGeO 4 :Ln 3+ (Ln = Pr, Tm) are characterized based on measurements of the excitation/emission spectra and their decays. The experimental results indicate that germanate ceramics Li 2 MgGeO 4 doped with trivalent rare earth ions can be applied as inorganic phosphors emitting orange (Pr 3+ ) or blue (Tm 3+ ) light.