Luminescent properties and energy transfer mechanism from Tb^3＋ to Eu^3＋ in CaMoO_4：Tb^3＋,Eu^3＋）phosphors

A series of CaMoO_4：Tb~（3＋）,Eu~（3＋） phosphors were prepared by the method of precipitation. The structure and morphology of the phosphors were characterized by the X-ray diffraction（XRD） and field emission scanning electron microscopy（FE-SEM）. The photoluminescence properties of the prepared products were researched, and the energy transfer from Tb~（3＋） to Eu~（3＋） in CaMoO_4 phosphors was studied. By adjusting the doping concentration of Eu~（3＋） ions in CaMoO_4：Tb~（3＋）,Eu~（3＋） phosphors, the emitting color of the phosphors could be easily tuned from green to red. With Tb~（3＋） doped in the phosphors, the red luminescence of Eu~（3＋） by near UV excitation was significantly enhanced. The energy transfer efficiency, rate and average distance between Tb~（3＋） and Eu~（3＋） in CaMoO_4：5%Tb~（3＋）,x%Eu~（3＋）（mole percent） phosphors（x=0.3-10） were calculated. It was found that the interaction type between Tb~（3＋） and Eu~（3＋） was electric dipole-dipole interaction in the phosphors.