NaLa1-x(MoO4)2:Eu3+/Yb3 phosphors with doping concentrations of Eu3+ and Yb3+ (x=Eu3++Yb3+, Eu3+=0.05, 0.1,0.2 and Yb3+=0.2, 0.45) were successfully synthesized by the microwave-modified sol-gel method, and the upconversion andspectroscopic properties were investigated. Well-crystallized particles showed a fine and homogeneous morphology with particlesizes of 2-5µm. Under excitation at 980nm, NaLa0.5(MoO4)2:Eu0.05Yb0.45 particles exhibited a strong 525-nm emission bandand a weak 550-nm emission band in the green region, and a very weak 665-nm emission band in the red region. The strong525-nm emission in the green region corresponds to the 7F1→5D1 transition and the weak 550-nm emission in the green regioncorresponds to the 7F0→5D2 transition, while the very weak emission 665-nm band in the red region corresponds to the5D0→7F3 transition. The Raman spectra of the doped particles indicated the domination of strong peaks at higher frequenciesof 762, 890, 1358 and 1430cm−1 and weak peaks at lower frequencies of 323, 388 and 450cm−1 induced by the disorder ofthe [MoO4]2− groups with the incorporation of the Eu3+ and Yb3+ elements into the crystal lattice or by a new phase formation.

• Lim, Chang Sung(Department of Advanced Materials Science & Engineering, Hanseo University)