EPR and Optical Properties of UV-B Radiation-Emitting Gd3+-Doped BaLa2ZnO5 Host Prepared by Sol-Gel Method

摘要

A series of trivalent gadolinium ion-doped BaLa2ZnO5 phosphors was prepared by the sol-gel technique. Phase purity and crystal structure were confirmed by the Rietveld refinement. The morphology of the sample was studied by scanning electron microscopy. The effect of Gd3+ concentration on the luminescence of the BaLa2-xGdxZnO5 (x=0.01x0.15) samples was investigated by photoluminescence spectra. Under excitation at 273nm, all the samples showed ultraviolet emission near 314nm, generated by the (P7/2S7/2)-P-6-S-8 transition of Gd3+ ions. It was found that the emission intensity increased with the concentration of Gd3+ ions up to 0.15mol without concentration quenching. The electron paramagnetic resonance spectra of the Gd3+ ion-doped BaLa2ZnO5 phosphors indicated that the dopant ions occupied slightly distorted La3+ sites in the host lattice. Both the PL and EPR studies describe the excited and ground-state features of Gd3+ ions in the BaLa2ZnO5 host lattice.