Synthesis of Y2O3:Eu3+ micro- and nanophosphors by sol-gel process

In this paper, optical properties of Y2O3:Eu3+ micro- and nanophosphors synthesized by sol-gel process are reported. Citric acid and tartaric acid were employed as chelating agents. Different factors effecting structures and properties of the phosphors, such as concentration of Eu3+, sintered temperature and the ratio of metal ions to tartaric acid, were examined. Crystal structure of the particles was investigated by X-ray diffraction (XRD) technique. The results showed that the phosphor powders completely crystallized at 600 degrees C. Morphology and particle size of the phosphors were studied by scanning electron microscope (SEM) and transmission electron microscope (TEM). The particle size of the obtained phosphors varied from 1 to 6 mu m (using citric acid as chelating agent) and from 20 to 30 nm (using tartaric acid as chelating agent). Photoluminescence measurements of the Y2O3: Eu3+ particles showed red emission peaks at 610 - 612 nm (D-5(0)-> F-7(2)). The optimal molar concentration to obtain the highest photoluminescent intensity for the phosphors was 7% of Eu3+.