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CaMoO_4:Pr~(3+)/Yb~(3+) powder was successfully synthesized by a facile hydrothermal method. X-ray diffraction(XRD) patterns of samples confirmed tetragonal structure and morphology and sizes were confirmed by scanning electron microscopy(SEM) analyses. Particles consisted of regular micro-spheres with uniform sizes, the diameter of each sphere lay in the range of 3 to 4 μm. The up-conversion photoluminescence emission and its concentration dependence were investigated under infrared excitation at 980 nm. All the UC micro-particles exhibited the typical blue, green and red emissions. Dominant blue emissions originated from ~3P_0→~3H_4 and intense red emissions originated from ~3P0→~3F_2 transitions, and they both belonged to two-photon excitation processes in CaMoO_4: Yb~(3+)/Pr~(3+) powder. The optimum doping concentrations of Pr~(3+) and Yb~(3+) for the highest UC luminescence were 0.1 mol.% and 16 mol.%, respectively. The possible up-conversion mechanisms were discussed in detail. It was found that the UC emission could be well controlled from blue to green to white color by adjusting the concentration of Pr~(3+) ions in CaMoO_4:Pr~(3+)/Yb~(3+) microcrystal. So it is a candidate material for solid-state lasers, biological imaging, solar cells, and optical communications.
X-ray diffraction (XRD) patterns of samples confirmed tetragonal structure and morphology and sizes were confirmed by scanning electron microscopy (SEM The up-conversion photoluminescence emission and its concentration dependence were investigated under infrared excitation at 980 nm. All the UC micro-particles exhibited the typical blue, green and red emissions. Dominant blue emissions originated from ~ 3P_0 → ~ 3H_4 and intense red emissions originated from ~ 3P0 → ~ 3F_2 transitions, and they both belonged to two-photon excitation processes in CaMoO_4: The optimum doping concentrations of Pr ~ (3+) and Yb ~ (3+) for the highest UC luminescence were 0.1 mol.% And 16 mol.%, Respectively, The possible up-conversion mechanisms were discussed in deta il. It was found that the UC emission could be well controlled from blue to green to white color by adjusting the concentration of Pr ~ (3+) ions in CaMoO_4: Pr ~ (3 +) / Yb ~ (3+) microcrystal. So it is a candidate material for solid-state lasers, biological imaging, solar cells, and optical communications.