Cyclic Microwave-Modified Sol-Gel Process of NaY(MoO4)2:Eu~(3+)/Yb~(3+) Particles and their Upconversion Photoluminescence Properties

摘要

Double molybdate NaY_(1-x)(MoO4)2:Eu~(3+)/Yb~(3+) phosphors with doping concentrations of Eu~(3+) and Yb~(3+) (x = Eu~(3+) + Yb~(3+), Eu~(3+) = 0.05, 0.1, 0.2 and Yb~(3+) = 0.2,0.45) were successfully synthesized by the microwave-modified sol-gel process and the upconversion and spectroscopic properties were investigated. Well-crystallized particles showed a fine and homogeneous morphology with particle sizes of 2-5 μm. Under excitation at 980 nm, NaY_(0.5)(MoO4)2:Eu_(0.05)Yb_(0.45) particles exhibited a strong 475 nm emission band in the blue region and a weak 525 nm emission band in the green region and a very weak 615 nm emission band in the red region. Raman spectra of the doped particles indicated the domination of strong peaks at higher frequencies (794, 890,926,1370 and 1440 cm~(-1)) induced by the disorder of the [M0O4]~(2-) groups with the incorporation of the Eu~(3+) and Yb~(3+) elements into the crystal lattice or by a new phase formation.