Synthesis and luminescent properties of Tb3+ doped BaLa2ZnO5 nanoparticles

Nanophosphor powders of composition BaLa2ZnO5:Tb3+ have been synthesized via using urea assisted solution combustion method using metal nitrates as the precursor materials. The structural, morphological and luminescent properties have been investigated by powder X-ray diffraction (XRD) and photoluminescence (PL) spectroscopy. The Rietveld analysis showed that these nanophosphors crystallize in the tetrahedral phase with the 14/mcm (140) space group. The crystallite size was determined by Scherer formula and was found to be 70 nm. The photoluminescent excitation of these nanocrystals at 278 nm yielded the characteristic emission peaks at 545 nm and 489 nm due to D-5(4 ->) F-7(6) (magnetic-dipole) and( 5)D(4) -> F-7(5) (electric-dipole) transitions, respectively. The optimum activator concentration was found to be 3 mol% and the concentration quenching arising from the over-doping was attributed to the quadrupole-quadrupole interactions. The excellent luminescent profile of these nano-scaled particles suggests their auspicious applications in the solid-state lighting and display technology.