Luminescence of LiNbO3 polycrystalline ceramics: Effect of Sc2O3 and Lu2O3 doping

Sc2O3 and Lu2O3 doped LiNbO3 polycrystalline ceramics were prepared by the solid state reaction method. Structural, morphological and luminescence properties have been studied by X-ray diffraction, Raman spectroscopy, FE-SEM and Flurospectrometery respectively. From XRD, no structural changes have been observed in Sc2O3 and Lu2O3 doped LiNbO3. SEM images show clear and distinct grains. Strong violet luminescence at 414 nm and 435 nm were observed for all samples with excitation in UV region (370 nm). Apart from this, with excitation at 289 nm, blue emission at 473 nm in pure LiNbO3 is observed. With change in Sc2O3 dopant concentration, this peak is red shifted to 505 nm and 525 nm exhibiting green emission. Changes observed in Raman modes strongly support Stokes shift in luminescence peaks. Sc2O3 and Lu2O3 doped LiNbO3 can be used as an efficient luminescent material in violet, blue and green region under UV excitation.