Synthesis and photoluminescence properties of CaGd2(MoO4)4:Eu3+ red phosphors

The novel red-emitting Eu3+ ions activated CaGd2(MoO4)4 phosphors were prepared by a citrate sol-gel method. The X-ray diffraction patterns confirmed their tetragonal structure when the samples were annealed above 600 °C. The photoluminescence excitation spectra of CaGd2(MoO4)4:Eu3+ phosphors exhibited the charge transfer band (CTB) and intense f-f transitions of Eu3+ ion. The optimized annealing temperature and Eu3+ ion concentration were analyzed for CaGd2(MoO4)4:Eu3+ phosphors based on the dominant red (5D0→7F2) emission intensity under NUV (394 nm) excitation. All decay curves were well fitted by the single exponential function. These luminescent powders are expected to find potential applications such as WLEDs and optical display systems.