Eu<sup>3+</sup> 이온의 몰 비 변화에 따른 MgMoO<sub>4</sub>:Dy<sup>3+</sup>,Eu<sup>3+</sup> 형광체의 광학 특성

Abstract

The effects of Eu 3+ doping on the structural, morphological, and optical properties of MgMoO4:Dy 3+ ,Eu 3+ 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 Eu 3+ ions. The surface morphology of MgMoO4:Dy 3+ ,Eu 3+ phosphors was studied using scanning electron microscopy and the grains showed a tendency to agglomerate as the content of Eu 3+ 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 6 H15/2→ 6 P7/2 and 6 H15/2→ 4 M 21/2 transitions of Dy 3+ ions. The emission spectra of the Mg 0.85MoO4:10 mol% Dy 3+ phosphors without incorporating Eu 3+ ions revealed a strong yellow band centered at 573 nm resulting from the 4 F9/2→ 6 H13/2 transition of Dy 3+ . As the content of Eu 3+ 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 Eu 3+ . These results indicated that white light emission could be achieved by controlling the contents of the Dy 3+ and Eu 3+ ions incorporated into the MgMoO4 host crystal.