Effect of Li +-ion on enhancement of photoluminescence in Gd 2O 3:Eu 3+ nanophosphors prepared by combustion technique

Abstract

Gd 2O 3:Eu 3+ (4 mol%) nanophosphor co-doped with Li + ions have been synthesized by low-temperature solution combustion technique in a short time. Powder X-ray diffractometer (PXRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), UV–VIS and photoluminescence (PL) techniques have been employed to characterize the synthesized nanoparticles. It is found that the lattice of Gd 2O 3:Eu 3+ phosphor transforms from monoclinic to cubic as the Li +-ions are doped. Upon 254 nm excitation, the phosphor showed characteristic luminescence 5D 0 → 7F J ( J = 0–4) of the Eu 3+ ions. The electronic transition located at 626 nm ( 5D 0 → 7F 2) of Eu 3+ ions was stronger than the magnetic dipole transition located at 595 nm ( 5D 0 → 7F 1). Furthermore, the effects of the Li + co-doping as well as calcinations temperature on the PL properties have been studied. The results show that incorporation of Li + ions in Gd 2O 3:Eu 3+ lattice could induce a remarkable improvement of their PL intensity. The emission intensity was observed to be enhanced four times than that of with out Li +-doped Gd 2O 3:Eu 3+.