Abstract
The effects of Eu3+ doping on the structural, morphological, and optical properties of MgMoO4:Dy3+,Eu3+ phosphors prepared by solid-state reaction technique were investigated. XRD patterns exhibited that all the synthesized phosphors showed a monoclinic system with a dominant (220) diffraction peak, irrespective of the content of Eu3+ ions. The surface morphology of MgMoO4:Dy3+,Eu3+ phosphors was studied using scanning electron microscopy and the grains showed a tendency to agglomerate as the content of Eu3+ ions increased. The excitation spectra of the phosphor powders were composed of a strong charge transfer band centered at 294 nm in the range of 230~340 nm and two intense peaks at 354 and 389 nm, respectively, arising from the 6H15/2→6P7/2 and 6H15/2→ 4M21/2 transitions of Dy3+ ions. The emission spectra of the Mg0.85MoO4:10 mol% Dy3+ phosphors without incorporating Eu3+ ions revealed a strong yellow band centered at 573 nm resulting from the 4F9/2→6H13/2 transitionof Dy3+. As the content of Eu3+ was increased, the intensity of the yellow emission was gradually decreased, while that of red emission band located at 614 nm began to appear, approached a maximum value at 10 mol%, and then decreased at 15 mol% of Eu3+. These results indicated that white light emission could be achieved by controlling the contents of the Dy3+ and Eu3+ ions incorporated into the MgMoO4 host crystal.
