Luminescence Properties and Energy Transfer of Sm 3+ -Eu 3+ Co-Doped Gd 2 (MoO 4 ) 3 Red Phosphors

The red phosphor Gd2(MoO4)3:Eu3+,Sm3+ was prepared by sol-gel method. The morphology and luminescence characteristics of the phosphor particles were characterized by scanning electron microscopy (SEM) and fluorophotometer. The results showed that the phosphor had the advantages of small particle size and the uniform particle size distribution. The luminescence properties of Eu3+ ions in Gd1.37Eu0.6Sm0.03(MoO4)3 could be evidently improved by co-doping of Sm3+ ions, which was due to the efficient energy transfer process from Sm3+ to Eu3+ ions. The chromaticity coordinates for Eu3+ doped Gd1.4Eu0.6(MoO4)3 and Eu3+ and Sm3+ codoped Gd1.37Eu0.6Sm0.03(MoO4)3, are(0.662, 0.329) and (0.668, 0.331), respectively. Because of the introduction of Sm3+ into the red-emitting phosphors, the chromaticity coordinates of Gd1.37Eu0.6Sm0.03(MoO4)3 phosphor is closer to the standard values of International chromaticity coordinates(0.67, 0.33). So Gd1.37Eu0.6Sm0.03(MoO4)3 shows good prospect for red phosphors of white LED.